Loading patent…
AssigneeROLLS-ROYCE plc
InventorJeffrey D Willis
Estimating the term…
A three stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36,40,44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (76,78,80,92). The primary fuel and air mixing ducts (78,78) comprise first and second radial flow swirlers (60,62). The primary fuel injectors (64,66) inject fuel into the first and second swirlers (60,62). The primary fuel injectors (44,66) and the first and second swirlers (60,62) are arranged such the fuel to air ratio of the fuel and air flowing from the passages (61) of the first swirler (60) into the primary combustion zone (36) is different to the fuel to air ratio of the fuel and air flowing from the passages (65) of the second swirler (62) into the primary combustion zone (36). This produces an axial distribution of fuel in the primary combustion zone (36) which reduces the generation of harmful vibrations in the combustion chamber (28).
A combustion chamber comprising at least one combustion zone being defined by at least one peripheral wall and an upstream wall, a first fuel and air mixing duct being arranged to supply air into the at least one combustion zone to produce a first recirculating flow in the at least one combustion zone, a second fuel and air mixing duct being arranged to supply air into the at least one combustion zone to produce a second recirculating flow in the at least one combustion zone, the first and second fuel and air mixing ducts being arranged coaxially, fuel injector means being arranged to supply fuel into the first fuel and air mixing duct and fuel injector means being arranged to supply fuel into the second fuel and air mixing duct, the first and second fuel and air mixing ducts and the fuel injector means being arranged such that there is a predetermined difference in the amount, or proportion, of air and/or fuel supplied to the first and second fuel and air mixing ducts whereby the position of heat release in the first recirculating flow is downstream of the position of heat release in the second recirculating flow.
A method of operating a combustion chamber comprising at least one combustion zone being defined by at least one peripheral wall and an upstream wall, a first fuel and air mixing duct being arranged to supply air into the at least one combustion zone, a second fuel and air mixing duct being arranged to supply air into the at least one combustion zone, the first and second fuel and air mixing ducts being arranged coaxially, fuel injector means being arranged to supply fuel into the first fuel and air mixing duct, and fuel injector means being arranged to supply fuel into the second fuel and air mixing duct, the method comprising supplying air from the first fuel and air mixing duct to produce a first recirculating flow in the at least one combustion zone, supplying air from the second fuel and air mixing duct to produce a second recirculating flow in the combustion zone, supplying a predetermined difference in the amount, or proportion, of air to the first and second fuel and air mixing ducts and/or supplying a predetermined difference in the amount, or proportion, of fuel to the first and second fuel and air mixing ducts whereby the position of heat release in the first recirculating flow is downstream of the position of heat release in the second recirculating flow.
Dependencies are inferred from the claim text.