Rolls-royce Corporation

Jeffrey D Willis

Ian James Toon

Bernard W Boyce

James Melville

Paul Fletcher

Arthur B Griffin

Phillip P Walsh

John H Currin

Stephen J O'Dell

Keith Oag

Alan Knocker

Richard E Pollard

Samantha Hayes-Bradley

Nigel P Gibney

Norman E Deacon

Ian M Waddell

A three stage lean burn combustion chamber ( ) comprises a primary combustion zone ( ), a secondary combustion zone ( ) and a tertiary combustion zone ( ). Each of the combustion zones ( ) is supplied with premixed fuel and air by respective fuel and air mixing ducts ( ). The secondary fuel and air mixing duct ( ) has passages ( A) and apertures ( A) at its downstream end to supply air and fuel into the secondary combustion zone ( ) at a first position in the at least one combustion zone ( ) and the secondary fuel and air mixing duct ( ) has passages ( B) and apertures ( B) at its downstream end to supply air and fuel into the secondary combustion zone ( ) at a second position in the secondary combustion zone ( ) downstream from the first position. This axial distribution of fuel in the combustion zone ( ) reduces the generation of harmful vibrations in the combustion chamber ( ).

Combustion chamber

A combustion chamber assembly (,) comprises a primary, a secondary and a tertiary fuel and air mixing ducts (,) to supply fuel and air to primary, secondary and tertiary combustion zones (,). Each of the primary, secondary and tertiary fuel and air mixing ducts (,) comprises a pair of axial flow swirlers (,) arranged coaxially to swirl the air in opposite directions and fuel injectors (,) to supply fuel coaxially of the respective axial flow swirlers (,). Valves (,) are provided to control the supply of air to the primary and the secondary fuel and air mixing ducts (,) respectively. A duct (,) is arranged to supply cooling air and dilution air to the combustion chamber (,). The amount of air supplied to the primary, secondary and tertiary fuel and air mixing ducts (,) and the duct (,) is measured.

Combustion chamber with separate, valved air mixing passages for separate combustion zones

A gas turbine engine comprises a centrifugal compressor (,), an air diffuser (,), a heat exchanger (,), combustion apparatus (,), and first and second turbines (,). The combustion chamber assembly (,) comprises a primary, a secondary and a tertiary fuel and air mixing ducts (,). The compressor (,), diffuser (,), primary and secondary fuel and air mixing ducts (,) and turbines (,) all comprise means (,) for varying the mass flow area at their inlets such that in operation the amount of air mass through each component may be independently variable. Under part power conditions the mass flow is reduced and under full power conditions the mass flow is increased thereby maintaining a substantially constant gas cycle throughout the engine.

Gas turbine engine and a method of controlling a gas turbine engine

A three stage lean burn combustion chamber (,) comprises a primary combustion zone (,), a secondary combustion zone (,) and a tertiary combustion zone (,). Each of the combustion zones (,) is supplied with premixed fuel and air by respective fuel and air mixing ducts (,). The primary fuel and air mixing ducts (,) comprise first and second radial flow swirlers (,). The primary fuel injectors (,) inject fuel into the first and second swirlers (,). The primary fuel injectors (,) and the first and second swirlers (,) are arranged such the fuel to air ratio of the fuel and air flowing from the passages (,) of the first swirler (,) into the primary combustion zone (,) is different to the fuel to air ratio of the fuel and air flowing from the passages (,) of the second swirler (,) into the primary combustion zone (,). This produces an axial distribution of fuel in the primary combustion zone (,) which reduces the generation of harmful vibrations in the combustion chamber (,).

Combustion chamber comprising mixing ducts with fuel injectors varying in number and cross-sectional area

A gas turbine engine combustion chamber comprises a primary combustion zone and a secondary combustion zone downstream of the primary combustion zone. A catalytic combustion zone is arranged downstream of the secondary combustion zone and a homogeneous combustion zone is arranged downstream of the catalytic combustion zone. A pilot injector supplies fuel into the primary combustion zone. At least one primary premixing duct has a plurality of primary fuel injectors to supply a first mixture of fuel and air into the primary combustion zone. A secondary premixing duct has a plurality of secondary fuel injectors to supply a second mixture of fuel and air into the secondary combustion zone. A plurality of temperature sensors are arranged at the intake to the catalytic combustion zone and a processor controls the valves which adjust the supply of fuel the fuel injectors to ensure that the temperature at the intake to the catalytic combustion zone remains in a predetermined temperature range.

Gas turbine engine combustion chamber having premixed homogeneous

Gas turbine engine combustion chamber

A gas turbine engine combustion chamber which has primary, secondary and tertiary combustion zones in flow series has a secondary fuel and air mixing duct and a tertiary fuel and air mixing duct. The secondary mixing duct has a secondary air intake at its upstream end and the tertiary mixing duct has a tertiary air intake at its upstream end. The tertiary air intake is arranged adjacent to the secondary air intake. A combined secondary and tertiary fuel system is provided to supply fuel to the secondary and tertiary mixing ducts. The fuel system comprises a manifold arranged adjacent to the secondary mixing duct but is spaced from the tertiary mixing duct by the secondary mixing duct. The manifold has apertures to direct fuel towards the tertiary air intake across the secondary air intake. Variations in fuel pressure cause the fuel to flow into the secondary air intake or the tertiary air intake.

A gas turbine engine combustion chamber has primary and secondary combustion zones. An annular secondary fuel and air mixing duct surrounds the primary combustion zone. The annular secondary fuel and air mixing duct is defined at its radially outer extremity by an annular wall. The annular wall is at least partially formed by an annular manifold. The annular manifold has a number of radially inwardly extending fuel injectors which inject fuel into the secondary fuel and air mixing duct. The annular fuel manifold is mechanically isolated from the remaining portion of the annular wall by an annular gap. The annular fuel manifold is supported from the combustor casing by a fuel supply pipe which is secured to the combustor casing and the annular fuel manifold.

Staged gas turbine combustion chamber with counter swirling arrays of

A gas turbine engine fuel burner suitable for burning diesel fuel oil comprises an annular body and a center body coaxially located within the annular body so that an annular flow path is defined between them. At the upstream end of the burner an annular fuel manifold cooperates with the annular body and the center body to define two coaxial passages which direct air into the annular flow path with minimal turbulence. The low level of turbulence within the fuel burner reduces the possibility of spontaneous combustion occurring within the burner. The center body is hollow and is provided at its downstream end with an end cap which cooperates with the downstream end of the annular body to define a radial fuel/air mixture outlet. Air directed into the interior of the center body provides transpiration cooling of the end plate center portion and is also directed via passages to provide an air flow over the radially outer extent of the downstream face of the end cap to provide cooling thereof and prevent the build-up of carbon thereon.

Gas turbine engine fuel burner

Combustion apparatus for a gas turbine engine comprises a burner which is so configured and located within a combustion chamber so as to urge fuel and air mixture ejected therefrom into a fuel rich toroidal vortex in an upstream first combustion zone of the combustion chamber. Unburnt fuel from the first combustion zone is mixed with additional air in a second fuel weak combustion zone downstream of the first zone. Adjustment of the air to fuel ratios in the two combustion zones results in the reduction of smoke and oxides of nitrogen reduction.

Combustion apparatus for a gas turbine

A dual fuel injector for a gas turbine power plant has fuel ducting including gas and liquid fuel ducts which can be removed easily for access to a nozzle of the fuel duct. A separate fluid ducting assembly is attached in the head of each combustor can and has an annular duct, a passage and drillings. The power plant is started on liquid fuel, and runs subsequently on gas produced in a coal gasifier. The flow of air through the duct and passage prevents any unburnt fuel or combustion products from entering the gas duct, and the flow through the drillings prevents carbon build up on face of the injector.

Dual fuel injectors

A gaseous fuel injector for an industrial gas turbine plant is arranged to operate on fuel produced from a coal gasifier for normal running or natural gas for starting purposes. The injector is self purging to prevent the ingestion of natural gas or combustion products into the passage of the fuel injector for the lower calorific value fuel. The fuel injector has fuel ducts and gas flow passages in a duct assembly attached to the head of each flame tube of a gas generator. For starting, natural gas flows through the duct and the central passage, while air flows through the outer passage preventing ingestion of natural gas and combustion products into the outer fuel duct. When running on fuel from a coal gasifier both ducts run full of fuel, as do the passages. The air for the coal gasifier may be provided by the gas generator.

Gas turbine engine gaseous fuel injector

A gas fuel injector for a gas turbine engine power plant is arranged to reduce the sensitivity of combustion efficiency to variations in gas fuel velocity injector exit at engine idle. The injector comprises a gas fuel duct which discharges gas fuel into a swirler assembly having passages of decreasing cross-sectional area, the passages also receiving a flow of compressor delivery air from the compressor of the power plant. There is an energy interchange between the gas fuel which may have a velocity of between 80 fps to 1000 fps depending on type of fuel, and the air such that the gas and air leave the injector at similar velocities. It has been found that if these velocities are matched, the combustion efficiency is less sensitive to gas velocity and produces higher combustion efficiencies than an arrangement whereby the velocity of the gas entering the system is dictated by the heat input requirements.

Gas fuel injector for wide range of calorific values

A dual fuel injector for a gas turbine engine is arranged to maintain pre-determined air fuel ratios in adjacent upstream and downstream opposite handed vortices and to reduce the deposition of carbon on the injector. The injector comprises a central duct, a deflecting member, a first radially directed outlet, and a shroud which defines an annular duct, and a second radially directed outlet. The ducts receive a supply of compressed air and the central duct receives gaseous fuel from an annular nozzle and the annular duct receives liquid fuel from a set of nozzles. When the injector is operating on liquid fuel, the fuel and air mixture issues from the second outlet and compressed air flows from the first outlet and prevents migration of fuel between the two vortices, thereby maintaining a rich air fuel ratio in the upstream vortex which reduces the emissions of NOx. Also, the flow of air from the first outlet reduces the deposition of carbon from the liquid fuels on the deflecting member.

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Coventry, United Kingdom

Jeffrey D Willis