Patent attributes
Methods and apparatus are disclosed for starting up a combined cycle plant using a startup duct to connect an auxiliary engine to the inlet of a plurality of HRSGs or other heat recovery systems. Each HRSG is fed by a combustion turbine. Dampers are supplied to isolate each HRSG from the startup duct and its CTG. The auxiliary engine is also ported to a stack allowing simple cycle operation. Dampers are also supplied to isolate the auxiliary engine from the startup duct and from its stack. During startups, the large CTGs will be isolated and the auxiliary engine will be connected to the HRSGs and started, allowing the HRSG to pressurize. As each HRSG pressurizes, it is isolated from the startup duct and connected to its respective CTG. The CTG is then started and loaded. The auxiliary engine is turned off and isolated when the last HRSG pressurizes.
