A premixing apparatus that mixes a fuel gas with air and supplies an air-fuel mixture in a burner through a fan includes a control device that is configured to carry out a third control that: calculates and memorizes a lower limit of a rotational speed of a fan, at which an increase of an opening degree of a variable throttle valve becomes necessary, as a first threshold; and when the rotational speed of the fan increases to the first threshold or faster next time, immediately changes the opening degree of the variable throttle valve to an increased opening degree, which is larger than a predetermined standard opening degree and is obtained by multiplying a deviation of the rotational speed of the fan from the first threshold by a predetermined coefficient.

A premixing apparatus that mixes a fuel gas with air and supplies an air-fuel mixture in a burner through a fan includes a control device that is configured to carry out a third control that: calculates and memorizes a lower limit of a rotational speed of a fan, at which an increase of an opening degree of a variable throttle valve becomes necessary, as a first threshold; and when the rotational speed of the fan increases to the first threshold or faster next time, immediately changes the opening degree of the variable throttle valve to an increased opening degree, which is larger than a predetermined standard opening degree and is obtained by multiplying a deviation of the rotational speed of the fan from the first threshold by a predetermined coefficient.

Combustors and gas turbines are provided. A combustor includes an axial centerline and an end cover. The combustor further includes at least one fuel nozzle that extends from the end cover and at is least partially surrounded by a combustion liner. The combustion liner extends between the at least one fuel nozzle and an aft frame and that defines a combustion chamber. An outer sleeve is spaced apart from and surrounds the combustion liner such that an annulus is defined therebetween. The outer sleeve defines at least one aperture. A wake energizer is mounted on the outer sleeve. The wake energizer defines at least one passage that is angled with respect to the axial centerline of the combustor. The at least one passage aligns and is in fluid communication with the at least one aperture of the outer sleeve.

A combustor includes: a combustor case; a combustor liner which is arranged in the combustor case and into which fuel is injected; and an air guide unit that is hollow and is formed to protrude from an inner surface of the combustor liner to inject air into an inside of the combustor liner, wherein the air guide unit includes: a first portion forming one end of the air guide unit and coupled to the inner surface of the combustor liner; and a second portion forming another end of the air guide unit and disposed in the combustor liner, and a size of the first portion is different from a size of the second portion.

Systems and methods are disclosed herein for passively managing cooling air in a gas turbine engine. A cooling air supply line may supply cooling air to a component in the gas turbine engine. A metering coupon may have a negative coefficient of thermal expansion. The metering coupon may allow more airflow through the metering coupon and through the component in response to an increase in temperature.

Systems and methods are disclosed herein for passively managing cooling air in a gas turbine engine. A cooling air supply line may supply cooling air to a component in the gas turbine engine. A metering coupon may have a negative coefficient of thermal expansion. The metering coupon may allow more airflow through the metering coupon and through the component in response to an increase in temperature.

A gas turbine engine includes: a combustor that combust the fuel and having an exit, a combustor exit temperature (T40) is the average temperature of flow and a combustor exit pressure (P40) is the total pressure there; a turbine including a rotor having a leading edge and a trailing edge, and wherein a turbine rotor entry temperature (T41) is an average temperature of flow at the leading edge and a turbine rotor entry pressure (P41) is the total pressure there; and a compressor having an exit, wherein a compressor exit temperature (T30) is the average temperature of flow at the exit from the compressor and a compressor exit pressure (P30) is the total pressure there (all at cruise conditions). A method of determining at least one fuel characteristic includes changing a fuel supplied to the engine; and determining a change in a relationship between T30 or P30, T40 and T41, or of P40 and P41, respectively.

A combustion chamber arrangement includes an annular outer and inner walls including at least one row of tiles. Each tile in the row of tiles has a rail extending towards and sealing with the outer wall and lip extending in a downstream direction from the row of tiles. The outer wall has a row of apertures to direct coolant onto the lips of the row of tiles. Each tile has a fastener positioned upstream of the rail and the fastener extends through a corresponding mounting aperture to secure the tile to the outer wall. The rail of each tile defines a plurality of slots with the outer wall and the slots are arranged in a region downstream of the corresponding fastener. None of the apertures in the row of apertures are in a region downstream of the tiles fastener. The arrangement reduces crack generation and propagation in the outer wall.

A turbine engine and method for controlling nitrogen oxides present within a combustor of the turbine engine. The turbine engine having a compressor section, a combustion section, and a turbine section in serial flow arrangement along an engine centerline. The combustion section having a combustor liner having a first end, a second end, opposing the first end, and at least partially defining a combustion chamber extending between the first and second ends. A dome assembly is mounted to the combustor liner at the first end and defines a dome inlet of the combustion chamber. There are multiple sets of dilution holes including a first set of dilution holes provided in the combustor liner downstream from the dome inlet and a second set of dilution holes provided in the combustor liner between the first set of dilution holes and the dome inlet.

A gas turbine arrangement for dual fuel operation has a first manifold that delivers a first fuel or compressor bleed fluid and is connected to a bleed port and a first passage for ejecting fuel or fluid into a combustor space. A second manifold delivers a second fuel and is connected to a second passage for ejecting the second fuel into the combustor space. A control system, when operated with the second fuel, provides the second fuel to the second manifold and continuously opens the bleed valve to provide bleed fluid into the first manifold to replace the first fuel. The control system controls the bleed valve over time by throttling a mass flow of the bleed fluid provided to the first passage or by increasing a mass flow of the bleed fluid provided to the first passage to adapt to fuel properties of the second fuel.