A method for operating a power plant, having at least one gas turbine engine and at least one fuel gas compressor, includes supplying fuel gas through a utility supply line, compressing the fuel gas to a plant supply pressure in the operating fuel gas compressor, and supplying the compressed fuel gas to a plant supply line. The gas turbine engine is operated at a set power output according to a power demand signal. If a failure of an operating fuel gas compressor is detected, the power output of the gas turbine engine is reduced to an emergency power output (which is lower than the set power output), and the power output of the gas turbine engine is restricted to the emergency power output. The reduction of the power output is performed in one single step and is controlled by at least one feedforward control signal.

There are described methods, systems, and assemblies for monitoring a bleed valve of a gas turbine engine. The method comprises determining a rate of change of a gas generator speed of the gas turbine engine; determining a rate of change of a parameter indicative of engine power of the gas turbine engine; comparing at least one ratio based on the rate of change of the gas generator speed and the rate of change of the parameter indicative of engine power to at least one range of values; detecting a modulation delay of the bleed valve when the at least one ratio is within the at least one range of values; and transmitting a signal indicative of the bleed valve malfunction in response to detecting the modulation delay.

A system and method for operating a combustion system comprising a fuel nozzle defining at least one main fuel circuit and at least one pilot fuel circuit is generally provided. The method includes determining an overall flow of fuel, the overall flow of fuel defining a sum total fuel through the main fuel circuit and the pilot fuel circuit; determining a plurality of ranges of ratios of main fuel flow through the main fuel circuit versus pilot fuel flow through the pilot circuit from the overall flow of fuel, wherein each range of ratios is based on a combustion criterion different from one another; determining a resultant range of ratios of main fuel flow versus pilot fuel flow based on a hierarchy of combustion criteria, wherein the hierarchy of combustion criteria provides a priority ranking of the combustion criterion; and flowing the overall flow of fuel to the main fuel circuit and the pilot fuel circuit based on the resultant range of ratios of main fuel flow versus pilot fuel flow.

A turbocharger control system includes a turbine; a fluid source of a pressurized fluid; an input valve fluidly coupled between the fluid source and an input of the turbine; a bypass valve fluidly coupled between the fluid source and an output of the turbine; a rotating machine operatively coupled to the turbine and configured to move a working fluid; and a control system communicably coupled to the input valve and the bypass valve. The control system is configured to perform operations including determining a level of the pressurized fluid in the fluid source; determining at least one of a flow rate or a pressure of a working fluid moved by the rotating machine; and operating the input valve and the bypass valve to change an operating state of the turbine from a first operating state to a second operating state.

A method for pressurizing exhaust gases from a turbine power plant includes the steps of: applying a pressure to at least a proportion, in particular a proportion rich in carbon dioxide, of the exhaust gases from the power plant by way of a fluid operating machine of a pressurization device, and applying a torque to the fluid operating machine and/or driving the fluid operating machine by way of such a torque, which is present at an output shaft of a main turbine of the power plant.

Herein provided are methods and systems for detecting a high temperature condition of a gas turbine engine. A fuel flow to a combustor of the engine and a compressor outlet pressure of the engine are obtained. A ratio of the fuel flow to the compressor outlet pressure is determined. The ratio is compared to a threshold and a high temperature condition of the engine is detected when the ratio exceeds the threshold.

Embodiments of the disclosure provide a method for controlling steam pressure within a turbine component. The method includes calculating a predicted stress on a rotor of the turbine component based on a predicted steam flow with the inlet valve in a minimum load position, a rotor surface temperature, and an inlet steam temperature, and determining whether the predicted stress exceeds a threshold. If the predicted stress exceeds the threshold, the inlet valve adjusts to a warming position. When steam in the discharge passage reaches a target pressure, the exhaust valve partially closes while maintaining the warming position of the inlet valve. If a safety parameter of the turbine component violates a boundary, the exhaust valve partially opens while maintaining the warming position of the inlet valve. When the predicted stress does not exceed the threshold, the inlet valve opens to at least the minimum load position.

Method for controlling a plural stage compressor comprising at least a first stage (10), a second stage (20) and a first inter-stage line (12) between the first stage (10) and the second stage (20), comprising the steps of: a—measuring the temperature at the inlet of the compressor, b—measuring the ratio between the outlet pressure (Pout) and the inlet pressure (Pin) of the first stage (10) of the compressor, c—calculating a coefficient (ψ) based at least on the value of the inlet temperature (Tin) and on the measured pressure ratio (Pout/Pin), d—if the calculated coefficient (ψ) is in a predetermined range, acting on a control valve (70; 76; 92) mounted in a line (4; 8) supplying the inlet of the first stage (10) of the compressor or in a gas recycle line (74) which opens into the first inter-stage line (12).

Systems, program products, and methods for adjusting operating limit (OL) thresholds for compressors of gas turbine systems based on mass flow loss are disclosed herein. The systems may include at least one computing device in communication with the gas turbine system, sensor(s) measuring operational characteristic(s) of the gas turbine system, and a pressure sensor measuring an ambient fluid pressure surrounding the gas turbine system. The computing device(s) may be configured to adjust operational parameters of the gas turbine system by performing processes including determining a mass flow loss between an estimated, first mass flow rate and a calculated, second mass flow rate for the compressor of the gas turbine system, and adjusting an OL threshold for the compressor of the gas turbine system based on the mass flow loss. The OL threshold for the compressor may be below a predetermined surge threshold for the compressor.

Method for controlling a plural stage compressor comprising at least a first stage (10), a second stage (20) and a first inter-stage line (12) between the first stage (10) and the second stage (20), comprising the steps of: a—measuring the temperature at the inlet of the compressor, b—measuring the ratio between the outlet pressure (Pout) and the inlet pressure (Pin) of the first stage (10) of the compressor, c—calculating a coefficient (ψ) based at least on the value of the inlet temperature (Tin) and on the measured pressure ratio (Pout/Pin), d—if the calculated coefficient (ψ)is in a predetermined range, acting on a control valve (70; 76; 92) mounted in a line (4; 8) supplying the inlet of the first stage (10) of the compressor or in a gas recycle line (74) which opens into the first inter-stage line (12).