PREDICTING NOx EMISSIONS

• US 20110106506A1
• Filed: 11/05/2009
• Published: 05/05/2011
• Est. Priority Date: 11/05/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Headley, Christopher Damien, Noel, Brian Stephen
• Granted Patent: US 8,244,505 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: F23N 2223/10 Correlation
• CPC Class Codes: F23N 2223/40 Simulation
• CPC Class Codes: F23N 2227/20 Calibrating devices
• CPC Class Codes: F23N 2900/05003 Measuring NOx content in flue gas
• CPC Class Codes: F23N 5/006 the detector being sensitive to oxygen

Abstract

A method of predicting a nitrogen oxide (NO_x) emission rate of a non-continuous, natural gas-fired boiler is presented. The method includes: calculating a correlation of the NO_x emission rate to a measured fuel flow rate and a sampled oxygen (O₂) concentration based on a plurality of sampled NO_x emission concentrations, measured fuel flow rates, and sampled (O₂) concentrations during operation of the non-continuous, natural gas-fired boiler using a computing device; calculating a predicted NO_x emission rate based on the correlation with the measured fuel flow rate and the sampled O₂ concentration using the computing device; and providing the predicted NO_x emission rate for use by a user.

Claims

1. A method for predicting a nitrogen oxide (NO_x) emission rate of a non-continuous, natural gas-fired boiler, the method comprising:

calculating a correlation of the NO_x emission rate to a measured fuel flow rate and a sampled oxygen (O₂) concentration based on a plurality of sampled NO_x emission concentrations, measured fuel flow rates, and sampled (O₂) concentrations during operation of the non-continuous, natural gas-fired boiler using a computing device;

calculating a predicted NO_x emission rate based on the correlation with the measured fuel flow rate and the sampled O₂ concentration using the computing device; and

providing the predicted NO_x emission rate for use by a user.

2. A method for predicting a NO_x emission rate according to claim 1, wherein the calculating of the correlation comprises:

sampling flue gas from the non-continuous, natural gas-fired boiler during operation at the plurality of measured fuel flow rates to obtain the plurality of corresponding sampled O₂ concentrations and sampled NO_x concentrations; and

calculating the correlation of the NO_x emission rate based on the plurality of measured fuel flow rates, and the plurality of corresponding sampled O₂ concentrations and sampled NO_x concentrations using the computerized device.

3. A method for predicting a NO_x emission rate according to claim 1, additionally comprising periodically recalculating the correlation using the computerized device.

4. A method for predicting a NO_x emission rate according to claim 1, wherein the calculating of the predicted NO_x emission rate comprises:

obtaining a fuel flow rate and a corresponding O₂ concentration of the non-continuous, natural gas-fired boiler during operation;

correlating the obtained fuel flow rate and corresponding obtained O₂ concentration with the correlation to arrive at the measured fuel flow rate and the sampled O₂ concentration using the computerized device; and

calculating the predicted NO_x emission rate based on the correlation with the measured fuel flow rate and the corresponding sampled O₂ concentration.

5. A method for predicting a NO_x emission rate according to claim 1, wherein the method is in accordance with 40 C.F.R. §

60.48b(f).

6. A predictive monitoring system for a nitrogen oxide (NO_x) emission rate comprising:

at least one device including;

a calculator for calculating a correlation of the NO_x emission rate to a measured fuel flow rate and a sampled oxygen (O₂) concentration based on a plurality of sampled NO_x emission concentrations, measured fuel flow rates, and sampled O₂ concentrations during operation of a non-continuous, natural gas-fired boiler; and

a calculator for calculating a predicted NO_x emission rate based on the correlation of the measured fuel flow rate and the sampled O₂ concentration.

7. A predictive monitoring system for a NO_x emission rate according to claim 6, wherein the predictor comprises:

a correlator for correlating an obtained fuel flow rate and corresponding obtained O₂ concentration with the correlation to arrive at the measured fuel flow rate and the corresponding sampled O₂ concentration.

8. A predictive monitoring system for a NO_x emission rate according to claim 6, wherein the monitoring system is maintained by:

calibrating a non-continuous, natural gas-fired boiler during operation;

calibrating the predictive monitoring system;

recording data related to either of the natural gas-fired boiler or the predictive monitoring system during calibration; and

reporting the data related to either of the natural gas-fired boiler or the predictive monitoring system resulting from calibration.

9. A predictive monitoring system for a NO_x emission rate according to claim 8, wherein the calibrating comprises calibrating components of the monitoring system selected from the group consisting of an oxygen analyzer, a computer system, and a natural gas fuel meter.

10. A predictive monitoring system for a NO_x emission rate according to claim 8, wherein the data is selected from the group consisting of a NO_x emission concentration, fuel flow rate, flue gas oxygen concentration, downtime of the predictive monitoring system, an audit result, a certification report for the predictive monitoring system, a natural gas certification for the predictive monitoring system, a calibration result, and a semiannual report.

11. A predictive monitoring system for a NO_x emission rate according to claim 6 additionally comprising a user interface for reporting the predicted NO_x emission rate.

12. A computer program comprising program code embodied in at least one computer-readable medium, which when executed, enables a computer system to implement a method of predicting a nitrogen oxide (NO_x) emission rate of a non-continuous, natural gas-fired boiler, the method comprising:

calculating a correlation of the NO_x emission rate to a measured fuel flow rate and a sampled oxygen (O₂) concentration based on a plurality of sampled NO_x emission concentrations, measured fuel flow rates, and sampled (O₂) concentrations during operation of the non-continuous, natural gas-fired boiler using a computing device;

calculating a predicted NO_x emission rate based on the correlation with the measured fuel flow rate and the sampled O₂ concentration using the computing device; and

providing the predicted NO_x emission rate for use by a user.

13. A computer program according to claim 12, wherein the calculating of the correlation comprises:

sampling flue gas from the non-continuous, natural gas-fired boiler during operation at the plurality of measured fuel flow rates to obtain the plurality of corresponding sampled O₂ concentrations and sampled NO_x concentrations; and

calculating the correlation of the NO_x emission rate based on the plurality of measured fuel flow rates, and the plurality of corresponding sampled O₂ concentrations and sampled NO_x concentrations using the computerized device.

14. A computer program according to claim 12, additionally comprising periodically recalculating the correlation using the computerized device.

15. A computer program according to claim 12, wherein the calculating of the predicted NO_x emission rate comprises:

obtaining a fuel flow rate and a corresponding O₂ concentration of the non-continuous, natural gas-fired boiler during operation;

correlating the obtained fuel flow rate and corresponding obtained O₂ concentration with the correlation to arrive at the measured fuel flow rate and the sampled O₂ concentration using the computerized device; and

calculating the predicted NO_x emission rate based on the correlation with the measured fuel flow rate and the corresponding sampled O₂ concentration.