# US 12,006,871 B2 · Fuel delivery system for delivering hydrogen fuel to a fuel injection system in a complex cycle gas turbine engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,871 B2 - Document ID: US12006871B2 - Status: Granted - Kind: B2 - Application number: 17/476,311 - Filed: 2021-09-15 - Published: 2022-03-31 - Granted: 2024-06-11 - Earliest claimed: 2020-09-30 - Assignees: ROLLS-ROYCE plc - Applicants: ROLLS-ROYCE plc - Inventors: Chloe J Palmer; John R Whurr - Web page: https://patentgrep.com/patent/US12006871B2 ## CPC - F02C 7/224: Heating fuel before feeding to the burner - F23R 3/283: {Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances} - F02C 3/20: using a special fuel, oxidant, or dilution fluid to generate the combustion products - F02C 3/22: the fuel or oxidant being gaseous at standard temperature and pressure (F02C3/28 takes precedence) - F02C 7/04: Air intakes for gas-turbine plants or jet-propulsion plants - F02C 7/14: of fluids in the plant {, e.g. lubricant or fuel (F02C7/185 takes precedence)} - F02C 7/143: before or between the compressor stages - F02C 7/18: the medium being gaseous, e.g. air {(F02C7/125 takes precedence)} - F02C 7/22: Fuel supply systems - F02C 7/222: {Fuel flow conduits, e.g. manifolds} - F02C 9/26: Control of fuel supply (F02C9/48 takes precedence; fuel valves F02C7/232) - F23D 14/32: using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air (F23D14/38 takes precedence) - F23R 3/04: Air inlet arrangements - F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)} - F23R 3/50: Combustion chambers comprising an annular flame tube within an annular casing (toroidal combustion chambers F23R3/52) - F02C 9/40: specially adapted to the use of a special fuel or a plurality of fuels - F05D 2260/213: by the provision of a heat exchanger within the cooling circuit - F23C 2900/9901: Combustion process using hydrogen, hydrogen peroxide water or brown gas as fuel - F23R 2900/00002: Gas turbine combustors adapted for fuels having low heating value [LHV] - Y02T 50/678: Aviation using fuels of non-fossil origin - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) - F23D: BURNERS - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F23C: METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN {A CARRIER GAS OR} AIR (burners F23D) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A complex cycle gas turbine engine for an aircraft with hydrogen fuel supply. The gas turbine engine comprises, in fluid flow series, a core gas turbine and a recuperator for heating hydrogen fuel prior to combustion by turbine exhaust products. ## Claims ### Claim 1 A complex cycle gas turbine engine for an aircraft with hydrogen fuel supply, comprising: in fluid flow series, a core gas turbine and a recuperator for heating hydrogen fuel prior to combustion by turbine exhaust products; and a fuel delivery system for delivering the hydrogen fuel from a cryogenic storage system to the recuperator, the fuel delivery system including a pump, a metering device, and a fuel heating system for heating the hydrogen fuel, wherein the metering device comprises a sonic fixed orifice configured to operate in a choked condition and a flow rate is controlled by adjusting pressure delivered by the pump upstream of the sonic fixed orifice based on a measured upstream temperature of the sonic fixed orifice and an area of the sonic fixed orifice, the fuel heating system comprises a vaporiser configured to vaporise liquid hydrogen from the cryogenic storage system, and the vaporiser comprises a fuel offtake for diverting a portion of the hydrogen fuel from a fuel conduit for combustion in a burner located in heat exchange relationship with the fuel conduit. ### Claim 2 (depends on 1) The gas turbine engine of claim 1, in which the core gas turbine engine comprises: a low-pressure spool having a low-pressure compressor driven by a low-pressure turbine; a high-pressure spool having a high-pressure compressor driven by a low high-pressure turbine. ### Claim 3 (depends on 2) The gas turbine engine of claim 2, further comprising a fan driven by the low-pressure spool, optionally via a reduction gearbox. ### Claim 4 (depends on 2) The gas turbine engine of claim 2, in which the core gas turbine comprises a combustor between the high-pressure compressor and the high-pressure turbine, the combustor having a liner cooled in a regenerative configuration by the hydrogen fuel. ### Claim 5 (depends on 2) The gas turbine engine of claim 2, further comprising a reheat combustor stationed between the high-pressure turbine and the low-pressure turbine. ### Claim 6 (depends on 1) The gas turbine engine claim 1, further comprising a fuel turbine for receiving heated hydrogen fuel from the spiral-wound recuperator to drive a load. ### Claim 7 (depends on 6) The gas turbine engine of claim 6, in which the load is: an electrical generator; a fuel pump for pumping the hydrogen fuel; a low-pressure spool or a high-pressure spool in the core gas turbine. ### Claim 8 (depends on 2) The gas turbine engine claim 2, further comprising an intercooler between the low-pressure compressor and the high-pressure compressor for cooling low-pressure compressor discharge air by the hydrogen fuel. ### Claim 9 (depends on 8) The gas turbine engine of claim 8, further comprising a second recuperator for further heating hydrogen fuel received from the intercooler. ### Claim 10 (depends on 9) The gas turbine engine of claim 9, in which the second recuperator is stationed downstream of the recuperator. ### Claim 11 (depends on 1) The gas turbine engine of claim 1, further comprising a reheat combustor. ### Claim 12 (depends on 11) The gas turbine engine of claim 11, in which the core gas turbine engine comprises a multi-stage turbine and the reheat combustor is stationed between two of the stages on the turbine. ### Claim 13 (depends on 1) The gas turbine engine of claim 1, in which the vaporiser comprises a boil volume or an electric heating element for initial heating of liquid hydrogen if no vaporised hydrogen fuel is available. ### Claim 14 (depends on 1) The gas turbine engine of claim 1, in which the flow rate is further controlled by varying the pressure ratio across the orifice. ### Claim 15 (depends on 1) The gas turbine engine of claim 1, in which the fuel heating system comprises one or more heat exchangers for heating the hydrogen fuel by heat from the core gas turbine. ### Claim 16 (depends on 1) The gas turbine engine of claim 1, in which one or more heat exchangers are oil-fuel heat exchangers for cooling engine oil or gearbox oil by the hydrogen fuel. ### Claim 17 (depends on 1) The gas turbine engine of claim 1, wherein the sonic fixed orifice comprises an exit with no expansion. ### Claim 18 (depends on 1) The gas turbine engine of claim 1, wherein a ratio of upstream to downstream pressures of the sonic fixed orifice is at least the critical pressure ratio of hydrogen. ### Claim 19 (depends on 1) The gas turbine engine of claim 1, wherein the recuperator is a spiral-wound recuperator.