Multifunctional water injection manifold device and operation method thereof

摘要

A multifunctional water injection manifold device for injecting water into a gas turbine combustor for NOx reduction is provided so that draining of the manifold may be done even in a load operation of gas turbine, and reverse flow of high temperature high pressure combustion gas is prevented so as not to cause eruptive breakage of the manifold. An air communication means is provided at the top portion of the manifold (51) for causing the manifold (51) to communicate with the air so that draining of the manifold (51) is done. A pressure type check valve (54) is interposed in branch pipe (6) between the manifold (51) and the combustor (1) so that water is supplied from the manifold (51) into the combustor (1) when differential pressure between the manifold (51) and the combustor (1) reaches a predetermined pressure or more and the water is stopped when the differential pressure is less than the predetermined pressure. Even if water injection is stopped during gas turbine load operation, the draining can be done without waiting for a no load state and following the draining of the manifold (51), sweeping of water holes (16) of injection nozzle (17) can be done upon stopping the gas turbine thereby to cause no coking of liquid fuel in the water holes (16).