Nonintrusive performance measurement of a gas turbine engine in real time

• US 9,746,360 B2
• Filed: 07/28/2014
• Issued: 08/29/2017
• Est. Priority Date: 03/13/2014
• Status: Expired due to Fees

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: DeSilva, Upul P., Claussen, Heiko
• Primary Examiner(s): Rodriguez, William H
• Application Number:
  US14/341,950
• Publication Number:
  US 20150260557A1
• Time in Patent Office: 1,128 Days
• Field of Search: 701100, 702 45, 702 48, 702 50, 702 54, 702 79, 702130, 702142, 702176, 374141, 374117-119, 374120, 374 45, 374147, 374144, 7386118-86131, 7320411-20427, 73587, 73597, 73598, 73602, 73645, 73660, 7311201
• CPC Class Codes: F02C 3/04 having a turbine driving a compressor power transmission arrangements F02C7/36; control of working fluid flow F02C9/16
• CPC Class Codes: G01F 1/66 by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters

Abstract

Performance of a gas turbine engine is monitored by computing a mass flow rate through the engine. Acoustic time-of-flight measurements are taken between acoustic transmitters and receivers in the flow path of the engine. The measurements are processed to determine average speeds of sound and gas flow velocities along those lines-of-sound. A volumetric flow rate in the flow path is computed using the gas flow velocities together with a representation of the flow path geometry. A gas density in the flow path is computed using the speeds of sound and a measured static pressure. The mass flow rate is calculated from the gas density and the volumetric flow rate.

Claims

1. A method for actively monitoring a mass flow rate of gas through a gas turbine engine, comprising:

receiving output signals generated by a plurality of acoustic sensors located on a first measurement plane, the output signals being indicative of thermoacoustic oscillations having contributions from acoustic signals from at least one acoustic transmitter in a gas flow path of the gas turbine engine wherein the at least one acoustic transmitter is located on a second measurement plane spaced apart from the first measurement plane wherein the first and second measurement planes are arranged transverse to the gas flow path and wherein the first and second measurement planes define a measurement zone that includes anticipated temperature variations in the gas flow path, the plurality of acoustic sensors and the at least one acoustic transmitter defining line-of-sound paths relative to each other in the gas flow path wherein the line-of-sound paths are located within the measurement zone;

determining, using a computer processor, a time-of-flight for the acoustic signals traveling along each of the line-of-sound paths;

processing, by the computer processor, the times-of-flight for the acoustic signals traveling along each of the line-of-sound paths to determine speeds of sound and gas flow velocity vectors along each of the line-of-sound paths;

computing, by the computer processor, a volumetric flow rate based on the of gas flow velocity vectors in the gas flow path and further based on a flow path geometry;

computing, by the computer processor, a gas density based on the speeds of sound along each of the line-of-sound paths and further based on a measured static pressure in the gas flow path; and

computing, by the computer processor, the gas mass flow rate based on the gas density and the volumetric flow rate.

2. The method of claim 1, the computing of the gas mass flow rate being described by the equation:

{dot over (m)}=ρ

·

{dot over (V)}

where {dot over (m)} is the mass flow rate, ρ

is the gas density and {dot over (V)} is the volumetric flow rate.

3. The method of claim 1, the computing of the gas density being described by the equation:

4. The method of claim 1, the determining of the time-of-flight being described by the equation:

5. The method of claim 1, wherein determining times of flight for the acoustic signals further comprises statistically smoothing a data series to reduce an impact of outliers.

6. The method of claim 1, wherein computing a volumetric flow rate comprises computing an average volumetric flow rate for the gas flow path.

7. The method of claim 1, wherein computing a volumetric flow rate comprises computing a volumetric flow rate mapping including volumetric flow rate values for a plurality of locations within the gas flow path.

8. The method of claim 1, wherein computing a gas density comprises computing an average gas density for the gas flow path.

9. The method of claim 1, wherein computing a gas density comprises computing a gas density mapping including gas density values for a plurality of locations within the gas flow path.

10. The method of claim 1, wherein:

transmitting acoustic signals from the at least one acoustic transmitter in a gas flow path of the gas turbine engine comprises transmitting the acoustic signals from a transmitter oriented at an angle of between 25 and 45 degrees to a first transverse plane through the flow path; and

receiving output signals generated by a plurality of acoustic sensors comprises receiving the output signals generated by a plurality of acoustic sensors oriented at an angle of between 25 and 45 degrees to second a transverse plane through the flow path offset from the first transverse plane.

11. The method of claim 1, further comprising:

evaluating a real-time performance of the gas turbine engine by determining a gas turbine power output using instantaneous inputs of the gas mass flow rate, a turbine exhaust energy and a turbine combustion energy.

12. The method of claim 1, wherein:

transmitting acoustic signals from at least one acoustic transmitter further comprises transmitting acoustic signals from at least one acoustic transceiver, each of the at least one acoustic transceivers comprising an acoustic transmitter and an acoustic sensor; and

receiving output signals generated by a plurality of acoustic sensors further comprises receiving output signals from a plurality of acoustic transceivers, each one of plurality of acoustic transceivers comprising an acoustic transmitter and an acoustic sensor.

13. The method of claim 12, further comprising:

receiving the measured static pressure in the gas flow path from static pressure sensors located on the acoustic transceivers.

14. The method of claim 1, where receiving output signals generated by a plurality of acoustic sensors comprises receiving output signals generated by at least 8 acoustic sensors.

15. The method of claim 1, where the plurality of acoustic sensors are acoustic sensors selected from a group consisting of capacitive sensors, piezoresistive sensors and fiber optic-based sensors.

16. The method of claim 1, where the at least one acoustic transmitter is an acoustic transmitter selected from a group consisting of an electrodynamic speaker, a piezoelectric acoustic transmitter, a mechanical gas-flow-activated acoustic transmitter and a spark gap acoustic transmitter.

17. A system for actively monitoring a mass flow rate of gas through a gas turbine engine, comprising:

at least one acoustic transmitter mounted to the gas turbine engine for transmitting acoustic signals in a gas flow path of the gas turbine engine wherein the at least one acoustic transmitter is located on a first measurement plane;

a plurality of acoustic sensors mounted to the gas turbine engine for receiving thermoacoustic oscillations having contributions from the acoustic signals in the gas flow path, wherein the plurality of acoustic sensors is located on a second measurement plane spaced apart from the first measurement plane wherein the first and second measurement planes are arranged transverse to the gas flow path and wherein the first and second planes define a measurement zone that includes anticipated temperature variations in the gas flow path, the plurality of acoustic sensors being further for generating output signals indicative of the thermoacoustic oscillations, the plurality of acoustic sensors and the at least one acoustic transmitter defining line-of-sound paths relative to each other in the gas flow path of the gas turbine engine wherein the line-of-sound paths are located within the measurement zone;

a processor connected to the plurality of acoustic sensors for receiving the output signals; and

computer readable media containing computer readable instructions that, when executed by the processor, cause the processor to perform the following operations;

determining a time-of-flight for the acoustic signals traveling along each of the line-of-sound paths;

processing the times-of-flight for the acoustic signals traveling along each of the line-of-sound paths to determine speeds of sound and gas flow velocity vectors along each of the line-of-sound paths;

computing a volumetric flow rate based on the of gas flow velocity vectors in the gas flow path and further based on a flow path geometry;

computing a gas density based on the speeds of sound along each of the line-of-sound paths and further based on a measured static pressure in the gas flow path; and

computing the gas mass flow rate based on the gas density and the volumetric flow rate.

18. The system of claim 17, wherein computing a volumetric flow rate comprises computing a volumetric flow rate mapping including volumetric flow rate values for a plurality of locations within the gas flow path.

19. The system of claim 17, wherein computing a gas density comprises computing a gas density mapping including gas density values for a plurality of locations within the gas flow path.

20. A non-transitory computer-readable medium having computer readable instructions stored thereon for execution by a processor to perform operations for actively monitoring a mass flow rate of gas through a gas turbine engine, the operations comprising:

receiving output signals generated by a plurality of acoustic sensors located on a first measurement plane, the output signals being indicative of thermoacoustic oscillations having contributions from acoustic signals from at least one acoustic transmitter in a gas flow path of the gas turbine engine wherein the at least one acoustic transmitter is located on a second measurement plane spaced apart from the first measurement plane wherein the first and second measurement planes are arranged transverse to the gas flow path and wherein the first and second measurement planes define a measurement zone that includes anticipated temperature variations in the gas flow path, the plurality of acoustic sensors and the at least one acoustic transmitter defining line-of-sound paths relative to each other in the gas flow path wherein the line-of-sound paths are located within the measurement zone;

determining, using the processor, a time-of-flight for the acoustic signals traveling along each of the line-of-sound paths;

processing, by the processor, the times-of-flight for the acoustic signals traveling along each of the line-of-sound paths to determine speeds of sound and gas flow velocity vectors along each of the line-of-sound paths;

computing, by the processor, a volumetric flow rate based on the of gas flow velocity vectors in the gas flow path and further based on a flow path geometry;

computing, by the processor, a gas density based on the speeds of sound along each of the line-of-sound paths and further based on a measured static pressure in the gas flow path; and

computing, by the processor, the gas mass flow rate based on the gas density and the volumetric flow rate.