Gas-turbine bearing oil system with improved oil return arrangement

• US 20090235632A1
• Filed: 02/19/2009
• Published: 09/24/2009
• Est. Priority Date: 02/19/2008
• Status: Active Grant

• Current Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Inventors: Pisseloup, Arnaud
• Granted Patent: US 8,281,563 B2
• Time in Patent Office: Days
• US Class Current: 60/39.80
• CPC Class Codes: F01D 25/20 using lubrication pumps
• CPC Class Codes: F01M 2001/123 using two or more pumps
• CPC Class Codes: F16N 2210/02 Turbines
• CPC Class Codes: F16N 2260/00 Fail safe
• CPC Class Codes: F16N 7/40 in a closed circulation system

Abstract

A gas-turbine bearing oil system with an oil supply arrangement includes at least one oil pump 5 supplying oil from an oil tank 1 to the bearing chambers 2, 3, 4 and at least one scavenge pump unit 6 returning oil from the bearing chambers 2, 3, 4 to the oil tank 1 At least one additional electric scavenge pump 7 is used to return oil from at least one bearing chamber 2, 3, 4 to the oil tank 1.

Claims

1. A gas turbine bearing oil supply system, comprising:

at least one oil pump for supplying oil from an oil tank to a plurality of bearing chambers;

at least one scavenge pump unit for returning oil from the bearing chambers to the oil tank; and

at least one additional electric scavenge pump for returning oil from at least one of the bearing chambers to the oil tank.

2. The system of claim 1, wherein the electric scavenge pump is actuatable upon standstill of the gas turbine.

3. The system of claim 1, wherein the electric scavenge pump is integrated into the scavenge pump unit.

4. The system of claim 1, wherein the electric scavenge pump is separately arranged from the scavenge pump unit.

5. The system of claim 4, and further comprising a scavenge line for operationally connecting the electric scavenge pump.

6. The system of claim 5, wherein the separate scavenge line includes a shut-off device.

7. The system of claim 6, wherein the shut-off device is mechanically actuatable by pressure differences between a bearing air and an internal pressure of the bearing chamber.

8. The system of claim 6, wherein the shut-off device is actuatable by an oil pressure in the system when the gas turbine is in operation.

9. The system of claim 1, wherein the electric scavenge pump is supplied with electric power via a gas turbine power supply.

10. The system of claim 1, wherein the electric scavenge pump is supplied with electric power via a separate battery.

11. A method for operating a gas turbine bearing oil supply system, comprising:

supplying oil from an oil tank to a plurality of bearing chambers with at least one oil pump during operation of the gas turbine;

returning oil from the bearing chambers to the oil tank with at least one scavenge pump unit during operation of the gas turbine; and

in the event of at least one of running down and shutting down of the gas turbine, returning oil from at least one of the bearing chambers to the oil tank with at least one electric scavenge pump.

12. The method of claim 11, and further comprising operating the electric scavenge pump only until residual oil is evacuated from the bearing chamber.

13. The method of claim 12, and further comprising operating the electric scavenge pump independently of whether a high-pressure shaft of the gas turbine is rotating.

14. The method of claim 13, and further comprising operating the electric scavenge pump to bypass mechanical pumps of the scavenge pump unit.

15. The method of claim 14, and further comprising isolating the electric scavenge pump from the mechanical pumps of the scavenge pump unit when the scavenge pump unit is operating.

16. The method of claim 15, and further comprising isolating the electric scavenge pump from the mechanical pumps of the scavenge pump unit dependent upon a pressure difference between a pressure source for bearing air and another pressure source of the bearing chamber.

17. The method of claim 11, and further comprising operating the electric scavenge pump independently of whether a high-pressure shaft of the gas turbine is rotating.

18. The method of claim 11, and further comprising operating the electric scavenge pump to bypass mechanical pumps of the scavenge pump unit.

19. The method of claim 11, and further comprising isolating the electric scavenge pump from the mechanical pumps of the scavenge pump unit when the scavenge pump unit is operating.

20. The method of claim 11, and further comprising isolating the electric scavenge pump from the mechanical pumps of the scavenge pump unit dependent upon a pressure difference between a pressure source for bearing air and another pressure source of the bearing chamber.