F factor method for determining heat rate and emission rates of a fossil-fired system

• US 6,691,054 B1
• Filed: 02/18/2003
• Issued: 02/10/2004
• Est. Priority Date: 03/24/1998
• Status: Expired due to Fees

• Current Assignee: Exergetic Systems LLC
• Original Assignee: Exergetic Systems LLC
• Inventors: Lang, Fred D
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Sun, Xiuqin
• Application Number:
  US10/371,498
• Time in Patent Office: 357 Days
• Field of Search: 702/100, 702/22, 702/182, 702/183, 700/286, 700/287, 700/274, 651/341, 651/361, 624/98, 622/10, 624/10, 454/192, 177/132, 162/198, 431/12, 420/62, 48/61, 481/97.R, 110/191, 237/2.A, 392/341, 445/01, 71/34
• US Class Current: 702/100
• CPC Class Codes: F22B 35/18 Applications of computers to steam boiler control
• CPC Class Codes: F23N 2221/08 Preheating the air
• CPC Class Codes: F23N 2223/40 Simulation
• CPC Class Codes: F23N 2225/22 heat losses
• CPC Class Codes: F23N 5/003 using detectors sensitive to combustion gas properties F23N5/02, F23N5/18 - F23N5/26 take precedence

Abstract

The operation of a fossil-fueled thermal system is quantified by employing the F Factor and other operating parameters to determine and monitor the unit'"'"'s heat rate and to determine the emission rates of its pollutants.

Claims

1. A method for quantifying the operation of a fossil-fired system, the method comprising the steps of:

obtaining a concentration ofthe effluent CO₂ found in theoretical combustion products from the fossil-fired system;

obtaining a total effluents flow rate from the fossil-fired system;

obtaining a correction factor for the total effluents flow rate, resulting in a corrected total effluents flow rate;

obtaining an F_C Factor;

obtaining a correction factor to the F_C Factor which converts its applicability from theoretical combustion to combustion associated with the fossil-fired system, and, if applicable, the correction for the system heating value base, resulting in a corrected F_C Factor; and

dividing the product of the corrected total effluents flow rate and the concentration of effluent CO₂ by the corrected F_C Factor, resulting in a total fuel energy flow of the system.

2. The method of claim 1, wherein the steps of obtaining the total effluents flow rate and obtaining the correction factor for the total effluents flow rate, includes the steps of:

obtaining a total effluents mass flow rate from the fossil-fired system; and

obtaining a correction factor for the total effluents mass flow rate, resulting in the corrected total effluents flow rate.

3. The method of claim 1, wherein the steps of obtaining the total effluents flow rate and obtaining the correction factor for the total effluents flow rate, includes the steps of:

obtaining a total effluents mass flow rate from the fossil-fired system;

obtaining a correction factor for the total effluents mass flow rate;

obtaining a conversion from moles to volume;

obtaining an average molecular weight of the total effluents; and

obtaining the corrected total effluents flow rate by combining the total effluents mass flow rate, the correction factor for the total effluents mass flow rate, the conversion from moles to volume, and the average molecular weight of the total effluents.

4. The method of claim 1, including additional steps, after the step of dividing, of:

obtaining a produced electrical power from the fossil-fired system; and

dividing the total fuel energy flow of the system by the produced electrical power, resulting in a heat rate of the fossil-fired system.

5. The method of claim 1, including additional steps, after the step of dividing, of:

obtaining a fuel heating value of the fuel consumed by the fossil-fired system; and

dividing the total fuel energy flow of the system by the fuel heating value, resulting in a fuel flow rate of the fossil-fired system.

6. The method of claim 5, including additional steps, after the step of dividing, of:

obtaining a turbine cycle energy flow;

obtaining a boiler efficiency;

obtaining a turbine cycle based fuel flow rate by dividing the turbine cycle energy flow by the product of the boiler efficiency and the fuel heating value; and

adjusting the turbine cycle energy flow until the turbine cycle based fuel flow rate and the fuel flow rate are in reasonable agreement.

7. The method of claim 1, including additional steps, after the step of dividing, of:

obtaining a fuel flow rate of the fossil-fired system; and

dividing the total fuel energy flow of the system by the fuel flow rate, resulting in the fuel heating value of the fuel consumed by the fossil-fired system.

8. The method of claim 7, including additional steps, after the step of dividing, of:

obtaining a turbine cycle energy flow;

obtaining a boiler efficiency;

obtaining a turbine cycle based fuel heating value by dividing the turbine cycle energy flow by the product of the boiler efficiency and the fuel flow rate; and

adjusting the turbine cycle energy flow until the turbine cycle based fuel heating value and the fuel heating value are in reasonable agreement.

9. The method of claim 1, wherein the step of obtaining the correction to the F_C Factor includes the steps of

obtaining a combustion air flow rate of the fossil-fired system by on-line monitoring;

obtaining a fuel flow rate of the fossil-fired system by on-line monitoring;

determining a correction for the system heating value base used by the fossil-fired system;

obtaining a set of correction factors applied to the combustion air flow rate and to the fuel flow rate which allow agreement between the system operator'"'"'s observations of heat rate and the predicted;

combining the combustion air flow rate, the fuel flow rate, the correction for the system heating value if applicable, and the set of correction factors resulting in the correction to the F_C Factor.

12. The method of claim 1, wherein the step of obtaining the concentration of the effluent CO₂ found in theoretical combustion products from the fossil-fired system includes the steps of:

obtaining a concentration of the effluent CO₂ found in actual combustion products from the fossil-fired system;

obtaining a correction factor which converts the concentration of the effluent CO₂ found in actual combustion products to the concentration ofthe effluent CO₂ found in theoretical combustion products, resulting in the concentration of the effluent CO₂ found in theoretical combustion products.

10. A method for quantifying the operation of a fossil-fired system through understanding the emission rate of a pollutant, the method comprising the steps of:

obtaining an F_C Factor;

obtaining a correction factor to the F_C Factor which converts its applicability from theoretical combustion to combustion associated with the fossil-fired system, and, if applicable, the correction for the system heating value base, resulting in a corrected F_C Factor;

measuring a concentration of a pollutant effluent;

obtaining a concentration ofthe effluent CO₂ found in theoretical combustion products from the fossil-fired system;

obtaining a conversion from moles to volume;

obtaining a set of molecular weights which include the average molecular weight of the total effluents based on actual combustion, the molecular weight ofthe total effluents based on theoretical combustion, and the molecular weight of the effluent; and

combining the corrected F_C Factor, the concentration of a pollutant effluent, the concentration of the effluent CO₂, the conversion from moles to volume, and the set of molecular weights resulting in the emission rate of a pollutant.

11. The method of claim 10, wherein the step of obtaining the concentration of the effluent CO₂ found in theoretical combustion products from the fossil-fired system includes the steps of:

obtaining a concentration of the effluent CO₂ found in actual combustion products from the fossil-fired system;

obtaining a correction factor which converts the concentration of the effluent CO₂ found in actual combustion products to the concentration ofthe effluent CO₂ found in theoretical combustion products, resulting in the concentration of the effluent CO₂ found in theoretical combustion products.