HYDROGEN BLENDED COMBUSTION SYSTEM WITH FLUE GAS RECIRCULATION

Abstract

A combined cycle power plant with flue gas recirculation that utilizes a blend of fuels containing hydrogen, to provide improved thermal efficiency and improved flame stability at high flue gas recirculation rates.

Description

BRIEF DESCRIPTION OF DRAWINGS

For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:

FIG. 1 is a schematic illustration of one embodiment in accordance with the present invention; and

FIG. 2 is a schematic illustration of a the duct burner as positioned in the transition duct between the gas turbine and the heat recovery stream generator, in accordance with one embodiment the present invention.

Claims

1. A combined cycle power plant comprising: a) a gas turbine, wherein said gas turbine produces an exhaust gas;b) a heat recovery steam generator, wherein said heat recovery steam generator comprises a duct burner;c) wherein said heat recovery steam generator generates a flue gas;d) wherein at least a portion of said flue gas is blended with the exhaust from the gas turbine before entering said duct burner, thereby producing a blended oxidant for said duct burner, ande) wherein a blended fuel is provided to the duct burner.

2. The power plant of claim 1, wherein said blended fuel comprises natural gas and hydrogen.

3. The power plant of claim 2, wherein said hydrogen comprises 20% of the total fuel flow rate by volume.

4. A method of increasing the efficiency of a combined cycle power plant comprising the steps of redirecting at least a portion of the flue gas from the heat recovery steam generator and mixing it with the exhaust from an associated gas turbine to form a mixed exhaust stream; introducing said mixed exhaust stream along with a blended fuel stream into a duct burner of said heat recovery steam generator.

5. The power plant of claim 4, wherein said blended fuel comprises natural gas and hydrogen.

6. The power plant of claim 5, wherein said hydrogen comprises 20% of the total fuel flow rate by volume.

7. A combined cycle power plant comprising: a) a gas turbine, wherein said gas turbine produces an exhaust gas, and wherein said exhaust gas exists said combined cycle power plant through a diverter valve and a bypass stack;b) heat recovery steam generator, wherein said heat recovery steam generator comprises a duct burner;c) wherein said heat recovery steam generator generates a flue gas;d) wherein at least a portion of said flue gas is blended with air before entering said duct burner, thereby producing a blended oxidant for said duct burner; ande) wherein a blended fuel is provided to the duct burner.

8. The power plant of claim 7, wherein said blended fuel comprises natural gas and hydrogen.

9. The power plant of claim 8, wherein said hydrogen comprises 20% of the total fuel flow rate by volume.

10. A combined cycle power plant comprising: a) a gas turbine, wherein said gas turbine is off-line;b) a heat recovery steam generator, wherein said heat recovery steam generator comprises a duct burner;c) wherein said heat recovery steam generator generates a flue gas;d) wherein at least a portion of said flue gas is blended with air before entering said duct burner, thereby producing a blended oxidant for said duct burner; ande) wherein a blended fuel is provided to the duct burner.

11. The power plant of claim 10, wherein said blended fuel comprises natural gas and hydrogen.

12. The power plant of claim 11, wherein said hydrogen comprises 20% of the total fuel flow rate by volume.