Gas turbine performance

Patent metadata

Field	Value
Publication number	US-12523376-B2
Application number	US-202418892721-A
Country	US
Kind code	B2
Filing date	Sep 23, 2024
Priority date	Jun 10, 2024
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A gas turbine engine for an aircraft is disclosed. The gas turbine engine comprises: a combustor, comprising a combustion chamber and a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber, wherein the plurality of fuel spray nozzles comprises a first subset of fuel spray nozzles and a second subset of fuel spray nozzles, wherein the combustor is operable in a condition in which each of the fuel spray nozzles of the first subset of fuel spray nozzles is supplied with fuel at a greater fuel flow rate than each of the fuel spray nozzles of the second subset of fuel spray nozzles, wherein a ratio of the number of fuel spray nozzles in the first subset of fuel spray nozzles to the number of fuel spray nozzles in the second subset of fuel spray nozzles is in the range of 1:3 to 1:6. A MTO nvPM emissions index ratio is defined as:
EI maxTO , SAF EI maxTO , FF
where: EI maxTO,SAF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for given operating conditions if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); and EI maxTO,FF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for the given operating conditions if a fuel provided to the plurality of fuel spray nozzles is a fossil-based hydrocarbon fuel. The MTO nvPM emissions index ratio of the gas turbine engine is less than 1. The gas turbine engine is configured to provide fuel comprising a SAF to the plurality of fuel spray nozzles. Also disclosed are methods of operating the gas turbine engine.

First claim

We claim:

1 . A gas turbine engine for an aircraft, comprising:
a combustor, comprising a combustion chamber and a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber, wherein the plurality of fuel spray nozzles comprises a first subset of fuel spray nozzles and a second subset of fuel spray nozzles, wherein the combustor is operable in a condition in which each of the fuel spray nozzles of the first subset of fuel spray nozzles is supplied with fuel at a greater fuel flow rate than each of the fuel spray nozzles of the second subset of fuel spray nozzles, wherein a ratio of the number of fuel spray nozzles in the first subset of fuel spray nozzles to the number of fuel spray nozzles in the second subset of fuel spray nozzles is in the range of 1:3 to 1:6; a fuel distribution system; and a controller configured to control the fuel distribution system to split fuel flow between the fuel spray nozzles of the combustor such that pilot injectors of the first subset of the fuel spray nozzles receive more fuel than pilot injectors of the second subset of the spray nozzles below a staging point, wherein the staging point is determined according to the composition of the fuel being provided to the plurality of fuel spray nozzles, wherein: a MTO nvPM emissions index ratio is defined as:

EI

maxTO
,
SAF

EI

maxTO
,
FF

where:
EI maxTO,SAF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for given operating conditions if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); and
EI maxTO,FF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for the given operating conditions if a fuel provided to the plurality of fuel spray nozzles is a fossil-based hydrocarbon fuel;

the MTO nvPM emissions index ratio of the gas turbine engine is less than 1; and
the gas turbine engine is configured to provide fuel comprising a SAF to the plurality of fuel spray nozzles.

2 . The gas turbine engine of claim 1 , wherein the MTO nvPM emissions index ratio is less than or equal to 0.93.

3 . The gas turbine engine of claim 1 , wherein the MTO nvPM emissions index ratio is greater than or equal to 0.15.

4 . The gas turbine engine of claim 1 , wherein:
a climb nvPM emissions index ratio is defined as:

EI

climb
,

S
⁢
A
⁢
F

EI

climb
,
FF

where:
EI climb,SAF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 85% available thrust for the given operating conditions, or for different given operating conditions, if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); and
EI climb,FF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 85% available thrust for the same given operating conditions at which EI climb,SA is calculated and if a fuel provided to the plurality of fuel spray nozzles is a fossil-based hydrocarbon fuel;
and the climb nvPM emissions index ratio of the gas turbine engine is less than 1.

5 . The gas turbine engine of claim 4 , wherein the climb nvPM emissions index ratio is less than or equal to 0.9.

6 . The gas turbine engine of claim 4 , wherein the climb nvPM emissions index ratio is greater than or equal to 0.1.

7 . The gas turbine engine of claim 1 , wherein:
an approach nvPM emissions index ratio is defined as:

EI

a
⁢
p
⁢
p
⁢
r
⁢
o
⁢
a
⁢
c
⁢
h

,

S
⁢
A
⁢
F

EI

a
⁢
p
⁢
p
⁢
r
⁢
o
⁢
a
⁢
c
⁢
h

,

F
⁢
F

where:
EI approach,SAF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 30% available thrust for the given operating conditions, or for different given operating conditions, if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); and
EI approach,FF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 30% available thrust for the same given operating conditions at which EI approach,SAF is calculated and if a fuel provided to the plurality of fuel spray nozzles is a fossil-based hydrocarbon fuel; and
the approach nvPM emissions index ratio of the gas turbine engine is less than 1.

8 . The gas turbine engine of claim 7 , wherein the approach nvPM emissions index ratio is less than or equal to 0.8.

9 . The gas turbine engine of claim 7 , wherein the approach nvPM emissions index ratio is greater than or equal to 0.03.

10 . The gas turbine engine of claim 1 , wherein:
an idle nvPM emissions index ratio is defined as:

EI

idle
,
SAF

EI

idle
,
FF

where:
EI idle,SAF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 7% available thrust for the given operating conditions, or for different given operating conditions, and if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); and
EI idle,FF is the nvPM emissions index in mg/kg of the ga

Assignees

• Rolls Royce Plc

Inventors

• Swann Peter
• Madden Christopher P

Classifications

• F02C7/22

  Fuel supply systems · CPC title

• F05D2270/08

  to produce clean exhaust gases · CPC title

• F02C3/20

  using a special fuel, oxidant, or dilution fluid to generate the combustion products · CPC title

• F02C7/228

  Dividing fuel between various burners · CPC title

• F23R3/34 Primary

  Feeding into different combustion zones · CPC title