Emissions of non-volatile particulate matter from gas turbine engines combusting sustainable aviation fuel and fossil-based hydrocarbon fuel

Patent metadata

Field	Value
Publication number	US-12553386-B2
Application number	US-202418892666-A
Country	US
Kind code	B2
Filing date	Sep 23, 2024
Priority date	Jun 10, 2024
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

A gas turbine engine includes: a rich burn, quick quench, lean burn combustor having a number of fuel spray nozzles in the range of 14-22 or a number of fuel spray nozzles per unit engine core size in the range 2 to 6. An MTO nvPM emissions index ratio is defined as:
EI max ⁢ TO , SAF EI max ⁢ TO , FF
where: EI maxTO,SAF and EI maxTO,FF are respectively 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 fuel spray nozzles includes a sustainable aviation fuel (SAF) or 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 including a SAF to the fuel spray nozzles. Also disclosed is a method of operating a gas turbine engine.

First claim

We claim:

1 . A gas turbine engine for an aircraft, comprising:
a rich burn, quick quench, lean burn (RQL) combustor having a number of fuel spray nozzles in the range of 14-22 or a number of fuel spray nozzles per unit engine core size in the range 2 to 6 where engine core size is defined, at a top of climb operating condition, as:

Core
⁢

size

=

m
.

2

⁢

T
3

P
3

,

where {dot over (m)} 2 =mass flow rate, in lbs per second, of air on entry to a high-pressure compressor, T 3 =temperature, in Kelvin, of air on exit from the high-pressure compressor, and P 3 =pressure, in lb inches per second squared per inch squared, of air on exit from the high-pressure compressor such that a unit of core size is expressed as:

s
·

K

1
2

·
in

;

and
wherein:
an 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 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 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 fuel spray nozzles, wherein
the fuel spray nozzles comprises one or more duplex nozzles and one or more single flow nozzles; and
the combustor comprises one or more ignitors each arranged adjacent to one or more of the duplex nozzles, and/or wherein the number of fuel spray nozzles per unit engine core size is in the range 2.5 to 4.5.

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
,
SAF

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 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,SAF is calculated and if a fuel provided to the fuel spray nozzles is a fossil-based hydrocarbon fuel;
and wherein 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

approach
,
SAF

EI

approach
,
FF

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 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 fuel spray nozzles is a fossil-based hydrocarbon fuel;
and wherein 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 fuel spray nozzles comprises a sustainable aviation fuel (SAF); and
EI idle,FF is the nvPM emissions index in mg/kg of the gas turbine engine when operating at around 7% available thrust for the same given operating conditions at which EI idle,SAF is calculated and if a fuel provided to the fuel spray nozzles is a fossil-based hydrocarbon fuel;
and wherein the idle nvPM emissions index ratio of the gas turbine engine

Assignees

• Rolls Royce Plc

Inventors

• Madden Christopher P
• Swann Peter

Classifications

• F05D2240/35

  Combustors or associated equipment · CPC title

• F05D2220/75

  equipment using fuel having a low calorific value, e.g. low BTU fuel, waste end, syngas, biomass fuel or flare gas · CPC title

• F02C7/228

  Dividing fuel between various burners · CPC title

• F02C7/22 Primary

  Fuel supply systems · CPC title

• F02C9/40 Primary

  specially adapted to the use of a special fuel or a plurality of fuels · CPC title