IP Library Granted Patent US 9,404,891
Granted Patent B2
US 9,404,891 · App. 14/109,470 · Granted Aug 2, 2016

Apparatus for and method of monitoring condensed water in steam pipes at high temperature

Inventors: Shyh-Shiuh Lih (La Canada Flintridge, CA); Hyeong Jae Lee (South Pasadena, CA); Yoseph Bar-Cohen (Seal Beach, CA); Xiaoqi Bao (San Gabriel, CA)
Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
G01N29/024G01F23/2962G01N29/4472G01N29/50G01N2291/02836G01N2291/044G01N2291/101
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Quick Facts
Patent No.
US 9,404,891
App. No.
14/109,470
Granted
Aug 2, 2016
Kind
B2
Abstract

A system and method for monitoring the properties of a fluid, such as water, in a steam pipe without mechanically penetrating the wall of the pipe. The system uses a piezoelectric transducer to launch an ultrasonic probe signal into the pipe. Reflected ultrasonic signals are captured in a transducer, which can be the same transducer that launched the probe signal. The reflected signals are subjected to data processing, which can include filtering, amplification, analog-to-digital conversion and autocorrelation analysis. A result is extracted which is indicative of a property of the fluid, such as a height of the condensed fluid, a cavitation of the condensed fluid, and a surface perturbation of the condensed fluid. The result can be recorded, displayed, and/or transmitted to another location. One embodiment of the system has been constructed and tested based on a general purpose programmable computer using instructions recorded in machine-readable non-volatile memory.

Claims (29)

1. A monitoring system for determining the status of a steam pipe, comprising:

a programmable computer which when operating under control of a set of instructions recorded on a machine readable memory performs the steps of:

controlling the emission of a probe ultrasonic signal having a frequency in the range of 2.25 Mega Hertz and above from an ultrasonic signal generator into a steam pipe;

receiving from an ultrasonic signal receiver an electrical signal representative of an ultrasonic response signal which is generated in said steam pipe in response to said probe ultrasonic signal;

processing said electrical signal by application of one or more of a filter, a moving average, a window, a transformation, a Shannon Energy Envelope and an autocorrelation method to produce a result representing a status of said steam pipe; and

performing at least one of recording said result, displaying said result, and transmitting said result to another system.

2. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said filter is selected from the group consisting of a low pass filter, a high pass filter and a band limit filter.

3. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said window is a predetermined searching window.

4. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said transformation is selected from the group consisting of a time to frequency domain transformation, Fourier Transform, a Hilbert Transform, and a Hilbert-Huang Transformation.

5. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said ultrasonic signal generator and said ultrasonic signal receiver are the same ultrasonic device.

6. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said programmable computer which when operating under control of a set of instructions recorded on a machine readable memory performs the additional step of converting said electrical signal from an analog signal to a digital signal.

7. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said result representing a status of said steam pipe includes information about liquid water in said stem pipe.

8. The monitoring system for determining the status of a steam pipe of claim 7 , wherein said information about liquid water in said steam pipe is indicative of a depth of said liquid water.

9. The monitoring system for determining the status of a steam pipe of claim 7 , wherein said information about liquid water in said steam pipe is indicative of at least one of a turbulent flow, of bubble generation, of cavitation, of a shock and of a vibration in said liquid water.

10. The monitoring system for determining the status of a steam pipe of claim 1 , wherein said programmable computer is a general purpose programmable computer.

11. A non-transitory machine-readable medium having recorded thereon a set of instructions, said instructions comprising only non-volatile signals, which when operating on a programmable computer causes said programmable computer to perform the steps of:

controlling the emission of a probe ultrasonic signal having a frequency in the range of 2.25 Mega Hertz and above from an ultrasonic signal generator into a steam pipe;

receiving from an ultrasonic signal receiver an electrical signal representative of an ultrasonic response signal which is generated in said steam pipe in response to said probe ultrasonic signal;

processing said electrical signal by application of one or more of a filter, a moving average, a window, a transformation, a Shannon Energy Envelope and an autocorrelation method to produce a result representing a status of said steam pipe; and

performing at least one of recording said result, displaying said result, and transmitting said result to another system.

12. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said filter is selected from the group consisting of a low pass filter, a high pass filter and a band limit filter.

13. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said window is a predetermined searching window.

14. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said transformation is selected from the group consisting of a time to frequency domain transformation, Fourier Transform, a Hilbert Transform, and a Hilbert-Huang Transformation.

15. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said ultrasonic signal generator and said ultrasonic signal receiver are the same ultrasonic device.

16. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said programmable computer is caused to perform the additional step of converting said electrical signal from an analog signal to a digital signal.

17. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said result representing a status of said steam pipe includes information about liquid water in said stem pipe.

18. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 17 , wherein said information about liquid water in said steam pipe is indicative of a depth of said liquid water.

19. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 17 , wherein said information about liquid water in said steam pipe is indicative of at least one of a turbulent flow, of bubble generation, of cavitation, of a shock and of a vibration in said liquid water.

20. The non-transitory machine-readable medium having recorded thereon a set of instructions of claim 11 , wherein said programmable computer is a general purpose programmable computer.

Assignments (1)
CONFIRMATORY LICENSE Recorded Jan 22, 2014
From: CALIFORNIA INSTITUTE OF TECHNOLGY
To: NASA
Reel/Frame 032161/0951 →
Continuity (3)
Continuation In Part 13043499 · Mar 9, 2011
Provisional Application 61312164 · Mar 9, 2010
Related Publication 20140107954A1 · Apr 17, 2014