Gas turbine engine systems and methods involving oil flow management

• US 8,746,404 B2
• Filed: 07/30/2008
• Issued: 06/10/2014
• Est. Priority Date: 07/30/2008
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Allam, Mahdy A.
• Primary Examiner(s): Siconolfi, Robert A
• Assistant Examiner(s): AUNG, SAN M
• Application Number:
  US12/182,265
• Publication Number:
  US 20100025158A1
• Time in Patent Office: 2,141 Days
• Field of Search: 184/6.11, 184/6.4, 184/55.1, 184/6.2, 184/6.3, 184/6.23, 184/6.28, 60/390.8, 137/85, 137/101, 137/596.15, 137/596.16
• US Class Current: 184/6.11
• CPC Class Codes: F01D 17/08 responsive to condition of working-fluid, e.g. pressure
• CPC Class Codes: F01D 19/00 Starting of machines or engines; Regulating, controlling, or safety means in connection therewith warming-up before starting F01D25/10; turning or inching gear F01D25/34
• CPC Class Codes: F01D 21/003 Arrangements for testing or measuring for measuring vibrations G01H
• CPC Class Codes: F01D 25/20 using lubrication pumps
• CPC Class Codes: F05D 2270/114 by limiting mechanical stresses
• CPC Class Codes: F05D 2270/301 Pressure
• CPC Class Codes: F05D 2270/304 Spool rotational speed
• CPC Class Codes: F05D 2270/708 with comparison tables

Abstract

Gas turbine engines systems and methods involving oil flow management are provided. In this regard, a oil pressure analysis system for a gas turbine engine is operative to: receive information corresponding to measured oil pressure and rotational speed during a start up of the engine; correlate the information into data sets, each of the data sets containing a measured oil pressure and a corresponding rotational speed; and determine whether the oil flow valve is functioning properly based on the information contained in the data sets.

Claims

1. An oil pressure analysis system for a gas turbine engine, the oil pressure analysis system having an oil flow valve and a pressure sensor located to detect the pressure of the oil downstream of the oil flow valve, the oil pressure analysis system being operative to:

receive information corresponding to measured oil pressure and rotational speed during a start up of the engine;

correlate the information into a first data subset and a second data subset, each of the data subsets contain a multiple of data sets in which each data set includes a measured oil pressure and a corresponding rotational speed, the second data subset separated from the first data subset by rotational speed;

calculate a minimum detected oil pressure (PMIN) and maximum detected oil pressure (PMAX) with a corresponding rotational speed based on the information contained in the data sets; and

determine whether the oil flow valve is functioning properly.

2. The system of claim 1, wherein the oil pressure analysis system is operative to determine whether the oil flow valve is functioning properly by analyzing sequential subsets of the data sets.

3. The system of claim 2, wherein each of the sequential data subsets contains six data sets.

4. The system of claim 1, wherein, responsive to determining that the oil flow valve is not functioning properly, the oil pressure analysis system provides a notification to a cockpit of an aircraft in which the system is installed.

12. The system of claim 1, further comprising, calculating

DELTA_P=PMAX−

PMIN;

DELTA_N2=100*(N2_PMIN−

N2_PMAX)/N2_PMIN; and

determine that the oil flow valve is open if the following three conditions are met;

1) PMAX is exhibited by any data set of a subset except for the last;

2) DELTA_P is greater than or equal to a threshold oil pressure; and

3) DELTA_N2 is greater than or equal to a nominal rotational speed.

5. A gas turbine engine comprising:

a compressor;

a turbine operative to drive the compressor, the turbine having a shaft interconnected with the compressor;

a first bearing operative to support the shaft;

an oil system having an oil flow valve operative to lubricate the bearing with oil; and

an oil pressure analysis system having a pressure sensor located to detect the pressure of the oil downstream of the oil flow valve, the oil pressure analysis system operative to;

receive information corresponding to detected oil pressures and rotational speeds during start up of the engine;

correlate the information into a first data subset and a second data subset, each of the data subsets contain a multiple of data sets in which each data set includes a measured oil pressure and a corresponding rotational speed, the second data subset separated from the first data subset by rotational speed;

calculate a minimum detected oil pressure (PMIN) and maximum detected oil pressure (PMAX) with a corresponding rotational speed based on the information contained in the data sets; and

determine whether the oil flow valve is functioning properly.

6. The engine of claim 5, wherein:

the engine has a second bearing;

the oil flow valve is operative to exhibit a first position, such that oil provided to the oil flow valve is directed to the first bearing, until the rotational speed of the engine corresponds to a first rotational speed; and

responsive to the first rotational speed, the oil flow valve is operative to exhibit a second position such that the oil provided to the oil flow valve is additionally directed to the second bearing.

7. The engine of claim 5, wherein:

the oil flow valve has an inlet, a first outlet and a second outlet; and

in first position, the oil flow valve is operative to route oil via the first outlet and not the second outlet and, in the second position, the oil flow valve is operative to route oil via the first outlet and the second outlet.

8. The engine of claim 7, wherein the oil flow valve is operative to exhibit the first position during at least a portion of starting of the engine.

9. The engine of claim 7, wherein the oil flow valve is operative to exhibit the first position until the rotational speed of the engine corresponds to a first rotational speed exhibited by the engine during start.

10. The engine of claim 9, wherein the oil flow valve is operative to maintain the second position during operation after the start.

11. The engine of claim 7, wherein the engine is a turbofan gas turbine engine.