System and method for stabilizing transcritical air-to-fuel heat exchange
AssigneesROLLS-ROYCE plc, Purdue Research Foundation
InventorsPatrick C. Sweeney, Stephen D. Heister, Steven A. Hunt, Carlo Scalo, Mario Tindaro Migliorino
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Abstract
A gas turbine engine includes devices, systems, and methods for design and operation of stabilizing heat exchangers for gas turbine engines in consideration of near supercritical fuel flow conditions.
Claims34
A method of operating a stabilizing heat exchanger of a gas turbine engine providing thermal communication between cooling air as a heat source and fuel as a heat sink to resist supercritical fluid oscillations, comprising
- providing a transcritical stability profile of the stabilizing heat exchanger based on a comparison between a dimensionless relationship of mean fuel pressure and dynamic fuel pressure (πf) and a dimensionless relationship of thermal energy transport and kinetic energy transport (πe) of the fuel, the transcritical stability profile defining a stable region and an unstable region of heat sink operations,
- determining a desired flowrate of the cooling air to be directed through the stabilizing heat exchanger that maintains the heat sink operations within the stable region according to current heat sink conditions, and
- bypassing a portion of the cooling air from entering the stabilizing heat exchanger to maintain the desired flowrate of the cooling air through the stabilizing heat exchanger.
A gas turbine engine comprising
- a fuel system adapted to provide fuel to a combustor of the engine in an amount ranging between a minimum and a maximum value according to engine operating parameters,
- a compressor for providing pressurized air to the combustor of the engine, and
- a stabilizing heat exchanger including a fuel side passage fluidly coupled with the fuel system to conduct fuel therethrough, an air side passage fluidly coupled with the compressor to receive pressurized air therethrough, the fuel side passage and the air side passage being arranged in thermal communication with each other, and a bypass valve arranged fluidly between the compressor and the air side passage to divert cooling air from entering the air side passage to maintain fuel within the fuel side passage in a stable region of a transcritical stability profile based on current operating conditions of the fuel within the fuel side passage.
A method of operating a stabilizing heat exchanger of a gas turbine engine providing thermal communication between cooling air as a heat source and fuel as a heat sink to resist supercritical fluid oscillations, comprising
- providing a transcritical stability profile of the stabilizing heat exchanger based on a comparison between a heat input rate and a pressure of the fuel, the transcritical stability profile defining a stable region and an unstable region of heat sink operations,
- determining a desired flowrate of the cooling air directed through the stabilizing heat exchanger that maintains the heat sink operations within the stable region according to current heat sink conditions, and
- bypassing a portion of the cooling air from entering the stabilizing heat exchanger to maintain the desired flowrate of the cooling air through the stabilizing heat exchanger.
Dependencies are inferred from the claim text.