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US 9,068,506 B2Granted
Turbine engine heat recuperator system
AssigneePratt & Whitney Canada Corp.
InventorsAndreas Eleftheriou, Daniel Alecu, David Menheere
Life of this patent
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Abstract
A gas turbine engine recuperator system includes a heat recuperator positioned in a gas turbine exhaust gas duct for recovering heat from turbine exhaust gases to preheat a compressor flow being supplied to the combustor. A continuous bleed flow of the turbine exhaust gases is provided to bypass the heat recuperator. The continuous bleed flow of the turbine exhaust gases is adjustable to reduce turbine exhaust gas pressure loss at a high engine operation level and to provide efficient heat recovery at low and/or medium engine operation levels.
Claims15
A turbine engine heat recuperator system comprising:
- a heat recuperator including first and second fluid passages configured for heat exchanges between fluid flowing through the respective first and second passages, the first passage of the heat recuperator being connected to and forming part of a compressor air passage to allow a compressor air flow to pass through the first passage of the heat recuperator and to then enter a combustor, the heat recuperator being disposed in an engine exhaust duct to allow exhaust gases discharged from a turbine to pass through the second passage of the heat recuperator and to then be discharged from the exhaust duct;
- a diffuser disposed between the turbine and the heat recuperator, the diffuser forming part of the exhaust duct to allow the exhaust gases to flow therethrough, the diffuser having a boundary wall defining a plurality of holes for continuously bleeding a boundary layer of the exhaust gases flowing through the diffuser;
- a valve device for adjusting a continuous bleed flow of the exhaust gases bled from the holes of the boundary wall of the diffuser;
- and
- a secondary passage for directing the adjusted continuous bleed flow of the exhaust gasses into the exhaust duct downstream of the heat recuperator, to thereby bypass the heat recuperator.
2 more elements
A gas turbine engine having a rotational axis, the engine comprising:
- an annular compressor assembly disposed about the rotational axis;
- an annular turbine assembly disposed about the rotational axis;
- an annular combustion gas generator assembly disposed about the rotational axis;
- and
- a heat recuperator system including:
- a heat recuperator including first and second fluid passages configured for heat exchanges between fluid flowing through the respective first and second passages, the first passage of the heat recuperator being connected to and forming part of compressor air passage to allow a compressor air flow from the annular compressor assembly to pass through the first passage of the heat recuperator and to then enter the annular combustion gas generator assembly, the heat recuperator being disposed in an annular exhaust duct to allow exhaust gases discharged from the annular turbine assembly to pass through the second passage of the heat recuperator and to then be discharged from the annular exhaust duct;
- an annular diffuser disposed between the annular turbine assembly and the heat recuperator, the annular diffuser forming part of the annular exhaust duct to direct the exhaust gases from the annular turbine assembly to flow therethrough and to the heat recuperator, the annular diffuser having an annular boundary wall defining a plurality of holes extending therethrough for continuously bleeding a boundary layer of the exhaust gases flowing through the diffuser;
- a valve device for adjusting a continuous bleed flow of the exhaust gases bled from the holes of the boundary wall of the diffuser;
- and
- a secondary passage for directing the adjusted continuous bleed flow of the exhaust gasses into the exhaust duct downstream of the heat recuperator.
7 more elements
A method for recuperating heat from exhaust gases discharged from a gas turbine engine, the method comprising:
- a) directing a compressor air flow through a heat exchanger disposed in a an exhaust duct of the engine, to a combustor of the engine;
- b) directing turbine exhaust gases through a diffuser disposed upstream of the heat exchanger and forming part of the exhaust duct, to thereby reduce a velocity of the turbine gases before the turbine gases pass though the heat exchanger;
- c) directing a main flow of the exhaust gases from the diffuser to pass through the heat exchanger and then discharging the main flow of the exhaust gases from the exhaust duct to atmosphere, thereby heating the compressor air flow passing through the heat exchanger;
- d) continuously bleeding a boundary layer of the turbine exhaust gases passing through a plurality of holes in a boundary wall of the diffuser to form a continuous flow of the turbine exhaust gases, and directing the continuous flow of the turbine exhaust gases to bypass the heat exchanger and to enter the exhaust duct downstream of the heat exchanger;
- and
- e) using a device for controlling the continuous bleed flow of the turbine exhaust gasses to bypass the heat exchanger to allow a low bleed rate when the engine is operated at low and medium power levels to provide effective heat recuperation, and to allow a high bleed rate when the engine is operated at a high power level to reduce pressure loss of the turbine exhaust gases.
3 more elements
Dependencies are inferred from the claim text.