Nonintrusive performance measurement of a gas turbine engine in real time

Patent metadata

Field	Value
Publication number	US-9746360-B2
Application number	US-201414341950-A
Country	US
Kind code	B2
Filing date	Jul 28, 2014
Priority date	Mar 13, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

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.

First claim

What is claimed is:

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:

ρ
=

m
⁢

⁢
P

n
⁢

⁢
R
⁢

⁢
T

where ρ is the gas density, m is mass of the gas, P is the measured static pressure in the gas flow path, n is a number of gas molecules, R is a universal gas constant and T is a mapping of a temperature of the gas.

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

t

B
⁢

⁢
C

=

∫
B
C

⁢

1

c
⁡

(

x
,
y
,
z

)

+

p
→

B
⁢

⁢
C

·

u
→

⁡

(

x
,
y
,
z

)

⁢

⁢
d
⁢

⁢
s

where:
t BC is the time of flight from a transmitter B to a sensor C;
c is a speed of sound in the gas flow for a temperature and gas constant;
{right arrow over (p)} BC is a unit vector along a line of sound path; and
{right arrow over (u)}(x, y, z) is a velocity vector in the gas flow.

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 , wher

Assignees

• Siemens Energy Inc

Inventors

• Desilva Upul P
• Claussen Heiko

Classifications

• G01F25/0007

  Physics · mapped topic

• G01M15/14

  Testing gas-turbine engines or jet-propulsion engines · CPC title

• G01F1/66 Primary

  by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters · CPC title

• F02C3/04 Primary

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title