Methods and systems for monitoring engine oil temperature of an operating engine

• US 8,850,876 B2
• Filed: 07/19/2012
• Issued: 10/07/2014
• Est. Priority Date: 07/19/2012
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Ertz, Timothy, Baron, Mike, Restivo, Anthony
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US13/553,516
• Publication Number:
  US 20140020460A1
• Time in Patent Office: 810 Days
• Field of Search: 731/145.5, 731/145.6
• US Class Current: 73/114.55
• CPC Class Codes: F01D 21/12 responsive to temperature

Abstract

Systems and methods for monitoring engine oil temperatures to detect higher than normal oil temperatures are provided. The system comprises a plurality of sensors for obtaining input signals from the operating engine for a predetermined set of engine conditions. At least one of the plurality of sensors includes an oil temperature sensor for measuring an engine oil temperature. The system also includes an engine control unit (ECU) where a plurality of predetermined limit values corresponding to at least one predetermined set of engine operating conditions is stored. The engine control unit is configured to select a predetermined limit value corresponding to a measured set of engine operating conditions, to calculate a maintenance limit value using the selected predetermined limit value, and to compare the measured oil temperature with the maintenance limit value. An output unit outputs a predetermined output depending on the result of the comparison.

Claims

1. A system for monitoring engine oil temperature of an operating engine comprising:

a plurality of sensors for obtaining sensor signals from the operating engine for a predetermined set of engine conditions, at least one of the plurality of sensors comprising an oil temperature sensor for measuring an engine oil temperature;

an engine control unit (ECU) where a plurality of predetermined limit values for engine oil temperatures corresponding to at least one predetermined set of engine operating conditions is stored, the engine control unit configured to select a predetermined limit value for the engine oil temperature corresponding to a measured set of engine operating conditions, to calculate a maintenance limit value using the selected predetermined limit value, and to compare the measured engine oil temperature with the maintenance limit value, the maintenance limit value defining a maximum engine oil temperature that the engine oil is allowed to reach before a predetermined warning is outputted; and

an output unit capable of outputting the predetermined warning depending on the result of the comparison.

2. The system of claim 1, wherein the predetermined warning comprises a maintenance-required oil temperature (MROT) warning and the engine control unit (ECU) comprises:

a calculator;

a Lookup table; and

a comparator for comparing the measured value of the measured engine oil temperature with the maintenance limit value, wherein the output unit outputs the maintenance-required oil temperature (MROT) warning when the measured value of the measured oil temperature exceeds the maintenance limit value but is below a HOT fault limit value.

3. The system of claim 2, wherein the predetermined limit value is determined from an algorithm that is a function of engine heat rejection, generator heat rejection, and oil cooler system performance.

4. The system of claim 2, wherein the maintenance limit value equals a sum of the predetermined limit value and a predetermined error value determined from the Lookup table.

5. A method for monitoring an engine oil temperature in an operating engine, the method comprising the steps of:

measuring the engine oil temperature to determine a measured value of the measured engine oil temperature;

measuring a predetermined set of engine operating conditions;

selecting a predetermined limit value for the engine oil temperature corresponding to the predetermined set of measured engine operating conditions among a stored set of predetermined limit values of engine oil temperatures;

calculating a maintenance limit value from the predetermined limit value and a predetermined error value, the maintenance limit value defining a maximum engine oil temperature that the engine oil is allowed to reach before a predetermined warning is outputted;

comparing the measured engine oil temperature with the maintenance limit value; and

outputting the predetermined warning corresponding to the result of the comparison through an output unit.

6. The method of claim 5, wherein the step of measuring a predetermined set of engine operating conditions comprises measuring engine load (bleed and shaft) and two or more of true airspeed, indicated airspeed, pressure altitude, density altitude, outside air temperature, altitude, inlet pressure, outside temperature, inlet temperature, engine shaft speed, oil temperature, and engine exhaust gas temperature.

7. The method of claim 5, wherein the steps of measuring the engine oil temperature and a predetermined set of engine operating conditions comprise obtaining sensor signals from the operating engine.

8. The method of claim 5, wherein the step of selecting a predetermined limit value comprises selecting the predetermined limit value determined from an algorithm that is a function of engine heat rejection, generator heat rejection, and oil cooler system performance.

9. The method of claim 5, wherein the step of calculating a maintenance limit value comprises adding the predetermined limit value and the predetermined error value.

10. The method of claim 5, wherein the step of calculating comprises obtaining the predetermined error value from a Lookup table.

11. The method of claim 5, wherein the step of outputting a predetermined warning comprises outputting a maintenance-required oil temperature (MROT) output signal if the measured engine oil temperature exceeds the maintenance limit value but is less than a single predetermined HOT fault limit value.

12. The method of claim 5, wherein the step of outputting a predetermined warning comprises outputting a first signal if the measured engine oil temperature exceeds the maintenance limit value and outputting a second signal if the measured engine oil temperature exceeds a single predetermined HOT fault limit value.

13. The method of claim 12, wherein the first signal comprises a maintenance-required output signal and the second signal comprises a HOT fault output signal.

14. A method for monitoring engine oil temperature of an operating engine, the method comprising the steps of:

measuring the engine oil temperature;

measuring a plurality of engine operating conditions;

selecting a predetermined limit value for the measured engine oil temperature among stored predetermined limit values corresponding to a predetermined set of measured engine operating conditions;

calculating a maintenance limit value for defining a maintenance-required oil temperature (MROT) condition, the maintenance limit value comprising a sum of the predetermined limit value and a predetermined error value;

detecting the MROT condition by comparing a measured value of the measured engine oil temperature with the maintenance limit value; and

outputting a MROT warning if the result of the comparison is that the measured value exceeds the maintenance limit value but is less than a single predetermined HOT fault limit value.

15. The method of claim 14, wherein the step of measuring a predetermined set of engine operating conditions comprises measuring two or more conditions comprising true airspeed, indicated airspeed, pressure altitude, density altitude, outside air temperature, inlet pressure, inlet temperature, engine load (bleed and/or shaft), engine shaft speed, oil temperature, or engine exhaust gas temperature.

16. The method of claim 14, wherein the step of calculating comprises obtaining the predetermined error value from a Lookup table.

17. The method of claim 14, wherein the step of outputting a MROT warning comprises outputting a maintenance-required oil temperature (MROT) output signal if the measured engine oil temperature exceeds a maintenance limit value but is less than the single predetermined HOT fault limit value.

18. The method of claim 14, wherein the step of outputting a MROT warning comprises outputting a first signal if the measured engine oil temperature exceeds the maintenance limit value and outputting a second signal if the measured engine oil temperature exceeds the single predetermined HOT fault limit value, wherein the first signal comprises a maintenance-required output signal and the second signal comprises a HOT fault output signal.

19. The method of claim 14, wherein the step of outputting an output further comprises outputting an output signal that a higher than normal oil temperature has been detected.