Method for switching over a gas turbine plant from gaseous fuel to liquid fuel and vice-versa

摘要

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.

主权项

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, and wherein, during switch over from liquid fuel to gaseous fuel, the second combustor is switched over before the first combustor.