A metal catalytic converter system employs an engine having an exhaust duct. A multistage metal catalytic converter is mounted in the exhaust duct. A compressor stage is mounted in the exhaust duct, the compressor stage configured to reduce exhaust backpressure created by the converter.

A controller for a gas turbine arranged to supply a load is described. The gas turbine includes a fuel supply arranged to supply fuel at a fuel flow rate to a combustor. The fuel supply includes a first fuel supply and a second fuel supply. The controller is arranged to control a proportion of the fuel flow rate supplied via the first fuel supply based, at least in part, on the fuel flow rate. A gas turbine includes such a controller and a method controls such a gas turbine.

A heat engine, in particular an aircraft engine, having a first compressor for supplying a combustion chamber of the heat engine with air and a first turbine arranged downstream of the combustion chamber for driving the first compressor, wherein the heat engine also has at least one steam supply line for supplying steam from a steam source into the combustion chamber. The heat engine also has a steam supply device, which has a second compressor and is designed to compress the working gas further by the second compressor as a function of a mass flow conducted through the steam supply line, before the working gas flows into the combustion chamber.

An aircraft has first and second fuel sources containing fuels with different characteristics, and one or more gas turbine engines powered by the fuels and each having a staged combustion system having pilot and main fuel injectors and being operable in pilot-only and pilot-and-main ranges of operation. The gas turbine engines each have a fuel delivery regulator arranged to control fuel delivery to the pilot and main fuel injectors. The method includes: obtaining a proposed mission description; obtaining nvPM impact parameters for the gas turbine engines, the impact parameters being associated with each operating condition of the proposed mission; calculating an optimised set of one or more fuel characteristics for each flight condition of the proposed flight defined in the flight description based on the nvPM impact parameters; and determining a fuel allocation based on the optimised set of one or more fuel characteristics.

A gas turbine engine for an aircraft. The gas turbine comprises a staged combustion system having pilot injectors and main injectors, a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors, and a fuel system controller. The controller is configured to identify an atmospheric condition, determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition, and inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control an index of soot emissions caused by combustion of fuel therein.

A gas turbine engine for an aircraft. The gas turbine comprises a staged combustion system having pilot injectors and main injectors, a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors, and a fuel system controller. The controller is configured to identify an atmospheric condition, determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition, and inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control an index of soot emissions caused by combustion of fuel therein.

A system is provided with a turbine combustor having a first diffusion fuel nozzle, wherein the first diffusion fuel nozzle is configured to produce a diffusion flame. The system includes a turbine driven by combustion products from the diffusion flame in the turbine combustor. The system also includes an exhaust gas compressor, wherein the exhaust gas compressor is configured to compress and route an exhaust gas from the turbine to the turbine combustor along an exhaust recirculation path. In addition, the system includes a control system configured to control flow rates of at least one oxidant and at least one fuel to the turbine combustor in a stoichiometric control mode and a non-stoichiometric control mode, wherein the stoichiometric control mode is configured to change the flow rates and provide a substantially stoichiometric ratio of the at least one fuel with the at least one oxidant, and the non-stoichiometric control mode is configured to change the flow rates and provide a non-stoichiometric ratio of the at least one fuel with the at least one oxidant.

Methods and apparatus to operate a gas turbine engine with hydrogen gas are disclosed. An example combustor nozzle apparatus of a gas turbine engine includes injecting an other combustible gas into a combustor, comparing a power output of the gas turbine to a rated power threshold, and in response to the power output of the gas turbine satisfying the rated power threshold: injecting water into the combustor, injecting hydrogen into the combustor, and terminating injections of the other combustible gas.

A metal catalytic converter system employs an engine having an exhaust duct. A multistage metal catalytic converter is mounted in the exhaust duct. A compressor stage is mounted in the exhaust duct, the compressor stage configured to reduce exhaust backpressure created by the converter.

A method for starting and stopping a gas turbine in a combined cycle power plant, wherein the gas turbine includes a compressor having adjustable guide vanes and the gas turbine power can also be controlled by opening the guide vanes. When the gas turbine is started, it is driven up to a base load or up to an emission-compliant load point, and the guide vanes are opened before the base load or the emission-compliant load point is reached.