Method for estimating the impact of fuel distribution and furnace configuration on fossil fuel-fired furnace emissions and corrosion responses

• US 20070239365A1
• Filed: 11/22/2006
• Published: 10/11/2007
• Est. Priority Date: 04/06/2006
• Status: Active Grant

• Current Assignee: Fuel and Furnace Consulting Incorporated
• Original Assignee: Fuel and Furnace Consulting Incorporated
• Inventors: Hanson, Simon P., Abbott, Murray F.
• Granted Patent: US 7,647,204 B2
• Time in Patent Office: Days
• US Class Current: 702/22
• CPC Class Codes: F27D 17/008 cleaning gases
• CPC Class Codes: F27D 19/00 Arrangements of controlling devices

Abstract

Provided is a method for estimating the impact of fuel distribution on emissions and corrosion responses of a fossil fuel-fired furnace. A variable is determined, termed herein separation number, by inputting fuel oil and air into the furnace, wherein the variable provides a linear relationship to multiple furnace process responses. Emission measurement equipment is located at an inlet and outlet of an SCR of the furnace and thermocouples are located in tubes of the furnace, wherein the responses can be measured to obtain operating data. This operating data is interpreted based on different modes of operation of the furnace, and a change is estimated in the responses as a function of the separation number, wherein the change can be quantified to determine an impact of the fuel distribution or the furnace configuration as a result of the operating data lying on a plane defined by the separation number and a load variable.

Claims

1. A method for estimating the impact of fuel distribution or furnace configuration on a fossil fuel-fired furnace, comprising the steps of:

determining a separation number, S, by inputting fuel oil and air into said furnace, wherein S provides a linear relationship to multiple furnace process responses;

locating emission measurement equipment at an inlet and outlet of an SCR of said furnace and locating thermocouples in tubes of said furnace, wherein said responses can be measured to obtain operating data;

interpreting said operating data based on different modes of operation of said furnace; and

,

estimating a change in said responses as a function of said separation number, wherein said change is quantified to determine an impact of said fuel distribution or said furnace configuration as a result of said operating data lying on a plane defined by said separation number and a load variable.

2. The method of claim 1, further comprising the step of obtaining fuel analyses for said fuel oil and converting said responses from a volumetric emission or mass emission per unit of energy to mass emission rate such that said separation number can be determined.

3. The method of claim 2, wherein said separation number is determined by the equation:

$S=\sqrt{\underset{i}{\sum <br><br>}<br><br>{\left(\frac{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{ok}}<br><br>x_{\mathrm{ik}}\right)}{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{ok}}\right)}-\frac{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{jk}}<br><br>x_{\mathrm{ik}}\right)}{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{jk}}\right)}\right)}^2}$

where {dot over (m)}_fk and {dot over (m)}_ok are a mass rate of said fuel oil and said air respectively through a port k of said furnace, and x_ik corresponds to x, y and z values of said port k.

4. The method of claim 1, wherein before the step of locating said emission measurement equipment, an initial data request is made to generating station personnel for current operational data and drawings.

5. The method of claim 4, wherein a geometry of said furnace is determined from said drawings to assist in the step of locating said emission measurement equipment.

6. The method of claim 1, wherein said responses measured are selected from the group consisting of windbox gas including combustion air and flue gas, NO_x emission at said inlet of said SCR, NO_x emission at said outlet of said SCR, furnace opacity, and furnace metal temperature.

7. The method of claim 6, wherein said responses are measured when a hopper dam is in an on or off position depending on said mode of operation of said furnace.

8. The method of claim 6, wherein a distribution of said windbox gas is determined from a method comprising the steps of:

analyzing over fire air velocity pressure data;

correlating windbox-furnace pressure differential data to windbox mass input less OFA flows;

distributing residual flow among burners; and

combining OFA analysis with burner results into a combined windbox gas distribution estimate.

9. A method for estimating the impact of fuel distribution or furnace configuration on a fossil fuel-fired furnace, comprising the steps of:

determining a variable, S, by inputting fuel oil and air into said furnace, wherein S provides a linear relationship to multiple furnace process responses;

locating emission measurement equipment at said furnace to obtain operating data;

interpreting said operating data based on different modes of operation of said furnace; and

,

estimating a change in said responses as a function of said variable S, wherein said change is quantified to determine an impact of said fuel distribution or said furnace configuration as a result of said operating data lying on a plane defined by said variable S and a load variable.

10. The method of claim 9, further comprising the step of obtaining fuel analyses for said fuel oil and converting said responses from a volumetric emission or mass emission per unit of energy to mass emission rate such that said variable can be determined.

11. The method of claim 10, wherein said variable S is determined by the equation:

$S=\sqrt{\underset{i}{\sum <br><br>}<br><br>{\left(\frac{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{ok}}<br><br>x_{\mathrm{ik}}\right)}{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{ok}}\right)}-\frac{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{jk}}<br><br>x_{\mathrm{ik}}\right)}{\underset{k}{\sum <br><br>}<br><br>\left({\stackrel{.}{m}}_{\mathrm{jk}}\right)}\right)}^2}$

where {dot over (m)}_fk and {dot over (m)}_ok are a mass rate of said fuel oil and said air respectively through a port k of said furnace, and x_ik corresponds to x, y and z values of said port k.

12. The method of claim 9, wherein before the step of locating said emission measurement equipment, an initial data request is made to generating station personnel for current operational data and drawings.

13. The method of claim 12, wherein a geometry of said furnace is determined from said drawings to assist in the step of locating said emission measurement equipment.

14. The method of claim 9, wherein said responses measured are selected from the group consisting of windbox gas including combustion air and flue gas, NO_x emission at an inlet of an SCR, NO_x emission at an outlet of an SCR, furnace opacity, and furnace metal temperature.

15. The method of claim 14, wherein said responses are measured when a hopper dam is in an on or off position depending on said mode of operation of said furnace.

16. The method of claim 14, wherein a distribution of said windbox gas is determined from a method comprising the steps of:

analyzing over fire air velocity pressure data;

correlating windbox-furnace pressure differential data to windbox mass input less OFA flows;

distributing residual flow among burners; and

combining OFA analysis with burner results into a combined windbox gas distribution estimate.