초록 ▼

In a method for switching over a gas turbine plant from gaseous fuel (16, 20) to liquid fuel (18, 22) and vice-versa, in which the gas turbine plant includes a first combustor and a second combustor fed with the flue gases of the first combustor, the first and second combustors are sequentially swit

In a method for switching over a gas turbine plant from gaseous fuel (16, 20) to liquid fuel (18, 22) and vice-versa, in which the gas turbine plant includes a first combustor and a second combustor fed with the flue gases of the first combustor, the first and second combustors are sequentially switched over while the other combustor maintains its operating conditions.

대표청구항 ▼

1. A method for switching over a sequential combustion gas turbine during continuous load operation from gaseous fuel to liquid fuel and from liquid fuel to gaseous fuel, wherein said sequential combustion gas turbine has in sequence: a first combustor, a second combustor fed with flue gases of the

1. A method for switching over a sequential combustion gas turbine during continuous load operation from gaseous fuel to liquid fuel and from liquid fuel to gaseous fuel, wherein said sequential combustion gas turbine has in sequence: a first combustor, a second combustor fed with flue gases of the first combustor, and a high-pressure turbine upstream of the second combustor and a low-pressure turbine downstream of the second combustor, the method comprising: sequentially switching over one of the first and second combustors while the other of the first and second combustors maintains a fuel flow rate to be substantially constant, and the sequential combustion gas turbine is controlled to deliver a substantially constant mechanical power during the switch over,wherein, during switch over from gaseous fuel to liquid fuel, the first combustor is switched over before the second combustor, andwherein, during switch over from liquid fuel to gaseous fuel, the second combustor is switched over before the first combustor. 2. A method as claimed in claim 1, wherein, during switch over, the first combustor operates at least partially with liquid fuel, while the second combustor operates at least partially with gaseous fuel. 3. A method as claimed in claim 1, further comprising: between the sequential switch over of the first and second combustor, providing a time delay. 4. A method as claimed in claim 1, wherein said gas turbine has a first gas turbine unit having said first combustor and a second gas turbine unit having said second combustor. 5. A method as claimed in claim 1, wherein during switchover from liquid fuel to gaseous fuel, in a first period, liquid fuel flow in the first combustor remains constant and simultaneously, liquid fuel flow in the second combustor decreases from 100% to 0% and gaseous fuel flow in the second combustor increases from 0% to 100%, and in a second period, the gaseous fuel flow in the second combustor remains constant and simultaneously, the liquid fuel flow in the first combustor decreases from 100% to 0% and gaseous fuel flow in the first combustor increases from 0% to 100%. 6. A method as claimed in claim 1, wherein during switchover from gaseous fuel to liquid fuel, in a first period, gaseous fuel flow in the second combustor remains constant and simultaneously, gaseous fuel flow in the first combustor decreases from 100% to 0% and liquid fuel flow in the first combustor increases from 0% to 100%, and in a second period, the liquid fuel flow in the first combustor remains constant and simultaneously, the gaseous fuel flow in the second combustor decreases from 100% to 0% and liquid fuel flow in the second combustor increases from 0% to 100%. 7. A method as claimed in claim 1, comprising: controlling, during switchover from gaseous fuel to liquid fuel, gaseous fuel flow in the first combustor decreases while liquid fuel flow in the first combustor increases, and while the gaseous fuel flow in the first combustor decreases and the liquid fuel flow in the first combustor increases, gaseous fuel flow in the second combustor remains constant. 8. A method as claimed in claim 7, comprising: controlling, during the switchover from gaseous fuel to liquid fuel, gaseous fuel flow in the second combustor decreases while liquid fuel flow in the second combustor increases, and while the gaseous fuel flow in the second combustor decreases and the liquid fuel flow in the second combustor increases, liquid fuel flow in the first combustor remains constant. 9. A method as claimed in claim 1, comprising: controlling, during switchover from liquid fuel to gaseous fuel, liquid fuel flow in the first combustor decreases while gaseous fuel flow in the first combustor increases, and while the liquid fuel flow in the first combustor decreases and the gaseous fuel flow in the first combustor increases, gaseous fuel flow in the second combustor remains constant. 10. A method as claimed in claim 9, comprising: controlling, during the switchover from liquid fuel to gaseous fuel, liquid fuel flow in the second combustor decreases while gaseous fuel flow in the second combustor increases, and while the liquid fuel flow in the second combustor decreases and the gaseous fuel flow in the second combustor increases, liquid fuel flow in the first combustor remains constant.