Method and system for assessing a condition of a boiler

Patent metadata

Field	Value
Publication number	US-11480332-B2
Application number	US-202117161759-A
Country	US
Kind code	B2
Filing date	Jan 29, 2021
Priority date	Jan 29, 2021
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A method and system of assessing a condition of a boiler is disclosed. The assessing of the condition of the boiler establishes a baseline resistivity of a boiler waterwall for a first location of the boiler waterwall under a known temperature condition. A resistivity of the first location is measured under another temperature condition. The measured resistivity for the first location is compared to the baseline resistivity. A condition of the waterwall of the boiler is determined based on the comparison.

First claim

What is claimed is:

1. A method of assessing a condition of a boiler, the method comprising:
providing a plurality of spaced resistivity sensing modules on a cold side of a waterwall of the boiler to form a matrix with each of the resistivity sensing modules representative of a measurement node in the matrix, each of the resistivity sensing modules including a communications interface enabling communication with the other resistivity sensing modules in the matrix and a control unit operatively coupled to the plurality of spaced resistivity sensing modules, a processing module, a four-wire sensing device, and a power source to power the communications interface, the processing module, and the four-wire sensing device based on electricity converted from heat harvested from the boiler waterwall; and
coordinating operation of the plurality of resistivity sensing modules with the control unit to obtain resistivity sensing measurements of the boiler waterwall, wherein the control unit permits only one of the resistivity sensing modules to obtain a resistivity sensing measurement at any time to avoid influence of the other resistivity sensing modules during the measurements, wherein obtaining the resistivity sensing measurements includes;
establishing a baseline resistivity of the boiler waterwall for a first location of a plurality of locations of the boiler waterwall under a known temperature condition;
measuring a resistivity for the first location of the plurality of locations of the boiler waterwall under another temperature condition;
comparing the measured resistivity for the first location to the baseline resistivity for the first location; and
determining a condition of the boiler waterwall based on the comparison.

2. The method according to claim 1 , wherein:
the condition of the boiler waterwall is at least one of slag buildup, ash buildup, corrosion or erosion on the cold side of the boiler waterwall, and erosion or corrosion inside a tube of the boiler waterwall.

3. The method according to claim 1 , further comprising:
measuring a resistivity at a second location of the plurality of locations;
comparing the measured resistivity for the second location to a baseline resistivity for the second location; and
determining the condition of the boiler waterwall based on at least one of the resistivity at the first location and the resistivity from the second location.

4. The method according to claim 3 , further comprising:
coordinating the resistivity measurements at each location of the plurality of locations so that at least one of the resistivity measurements at the plurality of locations occurs at a time different than that of at least another one of the resistivity measurements at another location of the plurality of locations.

5. The method according to claim 1 , wherein:
the establishing of the baseline resistivity of the boiler waterwall for the plurality of locations of the boiler waterwall comprises measuring a resistivity at a known constant temperature, at least at the first location of the plurality of locations.

6. The method according to claim 1 , further comprising:
compensating the resistivities measured based on a correlation of the electrical resistivity versus temperature at known temperatures for the boiler waterwall.

7. The method according to claim 1 ,
wherein each of the resistivity sensing modules in the matrix places a first pair of leads from the four-wire sensing device in electrical communication with the boiler waterwall at a first point, and places a second pair of leads from the four-wire sensing device in electrical communication with the boiler waterwall at a second point, wherein the second point is spaced from the first point by a known distance.

8. The method according to claim 7 , wherein:
the of measuring of the resistivity at the first location of the plurality of locations comprises applying a known current to the boiler waterwall from the first point to the second point at the first location, and measuring a voltage induced by the application of the known current from the first point to the second point.

9. The method according to claim 7 , wherein the providing of the plurality of spaced resistivity sensing modules on the cold side of the boiler waterwall comprises installing the resistivity sensing modules by at least one of welding, spot welding, brazing, bolting, screwing, epoxying, and soldering the first pair of leads and the second pair of leads to the boiler waterwall.

10. The method according to claim 1 , wherein:
the measuring of the resistivity at a first location of the plurality of locations comprises measuring the resistivity at least at a portion of the plurality of locations; and
wherein the method further comprises receiving, with the control unit, a plurality of measured resistivities corresponding to the at least a portion of the plurality of selected locations.

11. The method according to claim 10 , further comprising:
calculating an average resistivity or change of resistivity for the boiler waterwall based on at least two measured resistivities at the portion of the plurality of selected locations; and
based on the calculation, determining the condition of the boiler waterwall.

12. A system for assessing a condition of a boiler, comprising:
a plurality of spaced resistivity sensing modules disposed on a cold side of a waterwall of the boiler, the plurality of resistivity sensing modules forming a matrix with each of the resistivity sensing modules representative of a measurement node in the matrix, each of the resistivity sensing modules including a communications interface enabling communication with the other resistivity sensing modules in the matrix, a processing module, a four-wire sensing device, and a power source to power the communications interface, the processing module, and the four-wire sensing device based on electricity converted from heat harvested from the boiler waterwall, wherein each of the resistivity sensing modules is configured to apply a known current to the boiler waterwall via a first pair of leads from the four-wire sensing device and measure a voltage induced by the application of the current via a second pair of leads from the four-wire sensing device; and
a control unit operatively coupled to the plurality of spaced resistivity sensing modules, wherein the control unit is configured to coordinate operation of the plurality of resistivity sensing modules to obtain resistivity sensing measurements of the boiler waterwall, wherein the control unit permits only one of the resistivity sensing modules to obtain a resistivity sensing measurement at any time to avoid influence of the other resistivity sensing modules during the measurements,
wherein at least one of the resistivity sensing modules and the control unit are configured to determine a condition of the boiler waterwall based at least in part on the measured voltage.

13. The system of claim 12 , further comprising a temperature sensor, the temperature sensor operative to measure a temperature of the boiler waterwall, the temperature sensor in operative communication with at least one of the plurality of resistivity sensing modules and the control unit, wherein at least one of the plurality of resistivity sensing modules and the control unit are configured to determine a condition of the boiler waterwall.

14. The system of claim 12 , wherein:
the control unit is in communication with the plurality of resistivity sensing modules via a wireless network.

15. The system of claim 12 , wherein:
the power source of each of the resistivity sensing modul

Assignees

• Gen Electric

Inventors

• Ferry Allan Gunn

Classifications

• G01N27/20

  Investigating the presence of flaws · CPC title

• F23M5/08

  Cooling thereof; Tube walls · CPC title

• G01N27/041

  of a solid body · CPC title

• G01N27/22 Primary

  by investigating capacitance · CPC title

• F22B37/38 Primary

  Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes · CPC title