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

• US 7,647,204 B2
• Filed: 11/22/2006
• Issued: 01/12/2010
• Est. Priority Date: 04/06/2006
• Status: Expired due to Fees

• Current Assignee: Fuel and Furnace Consulting Incorporated
• Original Assignee: Fuel and Furnace Consulting Incorporated
• Inventors: Hanson, Simon P., Abbott, Murray F.
• Primary Examiner(s): Wachsman; Hal D
• Application Number:
  US11/562,491
• Publication Number:
  US 20070239365A1
• Time in Patent Office: 1,147 Days
• Field of Search: 702/182, 702/50, 702/140
• US Class Current: 702/182
• 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 various furnace outlet positions 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:

inputting fuel oil and air into said furnace;

determining a separation number, S, wherein in a planar plot taking into account a load variable, S provides a linear relationship to multiple furnace process responses, said load variable indicative of an amount of NO_x that is formed if all of said fuel oil and air were converted to said NO_x;

locating emission measurement equipment at an inlet and outlet of selective catalytic reactor of said furnace and locating thermocouples in tubes of said furnace, wherein said multiple furnace process 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 multiple furnace process 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 said planar plot defined by said separation number and said load variable.

2. The method of claim 1, further comprising the step of obtaining fuel analyses for said fuel oil and converting said multiple furnace process 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 multiple furnace process responses are selected from the group consisting of windbox gas including combustion air and flue gas, NO_x emission at said inlet of said selective catalytic reactor, NO_x emission at said outlet of said selective catalytic reactor, furnace opacity, and furnace metal temperature.

7. The method of claim 6, wherein said multiple furnace process 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 over fire air flows;

distributing residual flow among burners; and

combining over fire air 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:

inputting fuel oil and air into said furnace;

determining a variable, S, wherein in a planar plot taking into account a load variable, S provides a linear relationship to multiple furnace process responses, said load variable indicative of an amount of NO_x that is formed if all said fuel oil and said air were converted to said NO_x;

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 multiple furnace process 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 said planar plot defined by said variable S and said load variable.

10. The method of claim 9, further comprising the step of obtaining fuel analyses for said fuel oil and converting said multiple furnace process 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 multiple furnace process responses are selected from the group consisting of windbox gas including combustion air and flue gas, NO_x emission at an inlet of said selective catalytic reactor, NO_x emission at an outlet of said selective catalytic reactor, furnace opacity, and furnace metal temperature.

15. The method of claim 14, wherein said multiple furnace process 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 over fire air flows;

distributing residual flow among burners; and

combining over fire air analysis with burner results into a combined windbox gas distribution estimate.