Fuel recirculation thermal management system

Patent metadata

Field	Value
Publication number	US-10006366-B2
Application number	US-201514697880-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	Apr 28, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

The present disclosure provides systems and methods related to thermal management systems for gas turbine engines. For example, a thermal management system comprises a fuel circuit, comprising a burn line and a recirculation line, and a burn line fuel-oil cooler, coupled to the burn line and an oil circuit. The oil circuit comprises a sending portion, configured to carry oil from the burn line fuel-oil cooler to an engine lube system, and a returning portion, configured to carry oil from the engine lube system to the burn line fuel-oil cooler. The thermal management system further comprises a recirculation fuel-oil cooler, coupled to the recirculation line and the returning portion, and an air-fuel cooler coupled to the recirculation line.

First claim

What is claimed is:

1. A thermal management system, comprising:
a fuel circuit, comprising a burn line and a recirculation line;
a burn line fuel-oil cooler, coupled to the burn line and an oil circuit, comprising:
a sending portion, configured to carry oil from the burn line fuel-oil cooler to an engine lube system; and
a returning portion, configured to carry oil from the engine lube system to the burn line fuel-oil cooler;

a recirculation fuel-oil cooler, coupled to the recirculation line and the returning portion;
an air-fuel cooler coupled to the recirculation line; and
a fuel throttle valve disposed on the fuel circuit and configured to adjustably communicate fuel from the burn line into the recirculation line;
wherein the fuel circuit is configured to carry fuel from a fuel feed tank, through the burn line, and to the fuel throttle valve, at which a first portion of fuel is directed through the burn line and a second portion of fuel is optionally directed through the recirculation line, returning to the fuel feed tank; and
wherein the returning portion comprises:
a cooling line, coupled to, and configured to carry oil through, the recirculation fuel-oil cooler towards the burn line fuel-oil cooler; and
a bypass line, configured to carry oil towards the burn line fuel-oil cooler, substantially in parallel with the cooling line, and externally of the recirculation fuel-oil cooler.

2. The thermal management system of claim 1 , further comprising:
a first sensor, disposed on the oil circuit downstream of the burn line fuel-oil cooler and upstream of the recirculation fuel-oil cooler; and
a second sensor, disposed on the burn line downstream of the fuel throttle valve.

3. The thermal management system of claim 2 , wherein an integrated heat exchanger comprises the burn line fuel-oil cooler and the recirculation fuel-oil cooler.

4. The thermal management system of claim 2 , further comprising a bypass valve disposed on the returning portion and configured to adjustably control a flow of oil from the returning portion into at least one of the cooling line and the bypass line.

5. The thermal management system of claim 4 , wherein the bypass valve comprises a thermal valve.

6. The thermal management system of claim 4 , wherein the bypass valve comprises an electromechanical valve.

7. The thermal management system of claim 4 , further comprising a third sensor, disposed on the recirculation line downstream of the recirculation fuel-oil cooler.

8. The thermal management system of claim 7 , wherein at least one of the first sensor, the second sensor, and the third sensor is in communication with a controller.

9. The thermal management system of claim 8 , wherein the controller comprises a full authority digital engine control system.

10. The thermal management system of claim 7 , wherein an integrated bypass heat exchanger comprises the burn line fuel-oil cooler, the recirculation fuel-oil cooler, the bypass valve, the bypass line, and the cooling line.

11. The thermal management system of claim 10 , wherein at least one of the burn line fuel-oil cooler and the recirculation fuel-oil cooler comprises a tubular heat exchanger.

12. A method of transferring heat in a thermal management system, comprising:
circulating a volume of fuel in a fuel circuit, comprising a burn line and a recirculation line;
circulating a volume of oil in an oil circuit, comprising a sending portion and a returning portion;
transferring heat from the volume of oil to the volume of fuel in a burn line fuel-oil cooler coupled to the burn line;
dividing the volume of fuel, such that a first portion of fuel is communicated through a fuel throttle valve to a combustion section and a second portion of fuel is communicated through the fuel throttle valve and into the recirculation line;
transferring heat from the volume of oil to the second portion of fuel in a recirculation fuel-oil cooler coupled to the recirculation line and the returning portion;
transferring heat from the second portion of fuel to air in an air-fuel cooler coupled to the recirculation line;
determining, by a controller, an actual fuel temperature at a third location;
comparing, by the controller, the actual fuel temperature to a threshold fuel recirculation temperature; and
adjusting, by the controller, a bypass valve in response to the actual fuel temperature exceeding the threshold fuel recirculation temperature, wherein the bypass valve is disposed in the returning portion, wherein adjusting the bypass valve comprises controlling a flow of the volume of oil from the returning portion to at least one of:
a cooling line, coupled to, and configured to carry oil through, the recirculation fuel-oil cooler towards a burn line fuel-oil cooler; and
a bypass line, configured to carry oil towards the burn line fuel-oil cooler, substantially in parallel with the cooling line, and externally of the recirculation fuel-oil cooler.

13. The method of claim 12 , further comprising:
transferring the air externally from the thermal management system.

14. The method of claim 12 , further comprising:
determining, by a controller, at least one of an actual oil temperature at a first location and a second actual fuel temperature at a second location;
comparing, by the controller, at least one of the actual oil temperature to a threshold oil temperature and the second actual fuel temperature to a threshold fuel burn temperature; and
adjusting, by the controller, the fuel throttle valve in response to at least one of the actual oil temperature exceeding the threshold oil temperature and the second actual fuel temperature exceeding the threshold fuel burn temperature.

15. The method of claim 14 , wherein at least one of the actual oil temperature and the second actual fuel temperature is derived by the controller.

16. The method of claim 12 , wherein the actual fuel temperature is derived by the controller.

Assignees

• United Technologies Corp

Inventors

• Pickford Simon

Classifications

• F02C7/224

  Heating fuel before feeding to the burner · CPC title

• F28F27/02

  for controlling the distribution of heat-exchange media between different channels ({static flow control means in header boxes F28F9/026}; arrangements of guide plates or guide vanes F28F9/22, F28F25/12) · CPC title

• F02C7/16 Primary

  characterised by cooling medium · CPC title

• Y02T50/675

  Cross-Sectional Technologies · mapped topic

• F02C9/32

  characterised by throttling of fuel (F02C9/38 takes precedence) · CPC title