Gas turbine engine with cooling system

Patent metadata

Field	Value
Publication number	US-9759130-B2
Application number	US-201314033878-A
Country	US
Kind code	B2
Filing date	Sep 23, 2013
Priority date	Sep 28, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A cooling system for a gas turbine engine. The system includes a fuel air heat exchanger with a fuel passage that is in thermal contact with an engine cooling air passage. The system further includes a fuel deoxygenator located upstream of the fuel air heat exchanger and configured to deliver deoxygenated fuel to the fuel air heat exchanger fuel passage. The system also includes a valve configured to moderate engine cooling air flow to the engine cooling air passage.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
a staged combustor comprising a primary fuel injector and a secondary fuel injector;
a turbine having cooling passages;
an air line configured to provide engine cooling air to the cooling passages of the turbine;
a fuel line configured to provide fuel to the primary fuel injector and the secondary fuel injector of the combustor;
a first fuel air heat exchanger configured to exchange heat from the engine cooling air in the air line to fuel in the fuel line;
a fuel deoxygenator that is located upstream of the fuel air heat exchanger and that is configured to deoxygenate fuel in the fuel line;
a bypass passage configured to direct the engine cooling air around the fuel air heat exchanger;
a bypass valve configured to moderate engine cooling air flow rate through the fuel air heat exchanger and to moderate engine cooling air flow rate through the bypass passage, the bypass valve being upstream of the fuel air heat exchanger and the bypass valve being in fluid communication with the fuel air heat exchanger;
a temperature sensor configured to detect turbine inlet temperature; and
an electronic controller in signal communication with the temperature sensor configured to:
i) control the bypass valve according to the turbine inlet temperature to moderate air flow rate to maintain fuel temperature in the fuel line below a critical temperature,
ii) control the bypass valve such that the electronic controller provides instructions to the bypass valve to increase the engine cooling air through the heat exchanger when the fuel is below the is below the critical temperature, and
iii) maintain the fuel temperature below a critical temperature by reducing the engine cooling air through the heat exchanger.

2. The gas turbine engine according to claim 1 , wherein the critical temperature comprises a fuel oxidation temperature or a fuel pyrolysis temperature.

3. The gas turbine engine according to claim 2 , wherein the fuel oxidation temperature is at least partly dependent on the amount of dissolved oxygen in the fuel.

4. The gas turbine engine according to claim 1 , wherein the amount of oxygen dissolved in the fuel is at least partly dependent on flow rate of the fuel through the fuel line.

5. The gas turbine engine according to claim 1 , wherein:
the controller further comprises one or more of an engine core air flow sensor, a fuel flow rate sensor, and a fuel oxygen sensor, and
the controller is configured to control the bypass valve in response to any of a fuel temperature, an engine core air flow temperature, a nozzle guide vane inlet temperature, a high pressure nozzle guide vane inlet temperature, a flow rate through the fuel line, and the amount of oxygen dissolved in fuel flowing through the fuel line.

6. The gas turbine engine according to claim 1 , further comprising:
a second fuel air heat exchanger, wherein
the fuel line comprises a primary fuel line and a secondary fuel line,
the first fuel air heat exchanger comprises the primary fuel line configured to provide fuel to the primary fuel injector,
the second fuel air heat exchanger comprises the secondary fuel line configured to provide fuel to the secondary fuel injector,
the primary fuel line is in thermal contact with a primary air line, and
the gas turbine engine comprises a primary valve configured to moderate the flow of engine cooling air through the primary air line.

7. The gas turbine engine according to claim 1 , wherein the bypass valve is configured to switch air flow between the fuel air heat exchanger and the bypass passage.

8. A method of moderating an airflow rate in a gas turbine engine,
the gas turbine engine comprising:
a staged combustor comprising a primary fuel injector and a secondary fuel injector;
a turbine having cooling passages;
an air line configured to provide engine cooling air to the cooling passages of the turbine;
a fuel line configured to provide fuel to the primary fuel injector and the secondary fuel injector of the combustor;
a fuel air heat exchanger configured to exchange heat from the engine cooling air in the air line to fuel in the fuel line;
a fuel deoxygenator that is located upstream of the fuel air heat exchanger and that is configured to deoxygenate fuel in the fuel line;
a bypass passage configured to direct the engine cooling air around the fuel air heat exchanger;
a bypass valve configured to moderate the engine cooling air flow rate through the fuel air heat exchanger and to moderate engine cooling air flow rate through the bypass passage, the bypass valve being upstream of the fuel air heat exchanger and the bypass valve being in fluid communication with the fuel air heat exchanger; a temperature sensor configured to detect turbine inlet temperature; and an electronic controller,
the method comprising:
monitoring are turbine inlet temperature by the temperature sensor; and moderating engine cooling air flow through the fuel air heat exchanger according to the turbine inlet temperature to maintain fuel temperature in the fuel line below a critical temperature, and additionally controlling the bypass valve such that that an electronic controller provides instructions to the bypass valve to increase the engine cooling air through the heat exchanger when the fuel is below the is below the critical temperature while also maintaining the fuel temperature below the critical temperature by reducing the engine cooling air through the heat exchanger.

9. The method according to claim 8 , wherein the method comprises controlling the bypass valve in response to engine conditions comprising one or more of an engine component, a nozzle guide vane inlet temperature, a fuel flow rate through the fuel line, and a temperature of the fuel flowing through the fuel line.

10. The method according to claim 9 , wherein the method comprises reducing the engine cooling air flow when fuel flow in the fuel line falls below a first predetermined value, and increasing the engine cooling air flow when the fuel flow in the fuel line rises above a second predetermined value.

11. The method according to claim 9 , wherein the method comprises increasing the engine cooling air flow when fuel temperature in the fuel line falls below a first predetermined value, and reducing the engine cooling air flow when the fuel flow in the fuel line rises above a second predetermined value.

12. The method according to claim 8 , wherein the method comprises moderating the air flow rate through the fuel air heat exchanger with the bypass valve.

Assignees

• Rolls Royce Plc

Inventors

• Appukuttan Ajith
• Rolt Andrew Martin
• Moran Anthony John

Classifications

• F02C7/224

  Heating fuel before feeding to the burner · CPC title

• Y02T50/671

  Cross-Sectional Technologies · mapped topic

• Y02T50/675

  Cross-Sectional Technologies · mapped topic

• F02C7/185 Primary

  Cooling means for reducing the temperature of the cooling air or gas · CPC title

• F02C7/141 Primary

  of working fluid · CPC title