US Patent 10006313 Power plant with integrated fuel gas preheating

The invention refers to a CCPP comprising a gas turbine, a water steam cycle with a steam turbine and a HRSG with at least two pressure levels, and a fuel preheater for preheating the fuel of the gas turbine. The fuel preheater includes a first heat exchanger for preheating the fuel to a first elevated temperature, which is connected to a feed water line from a pressure level of the HRSG, which is below the highest HRSG pressure level, and a second heat exchanger for further preheating the fuel gas to a second elevated temperature, which is connected to the high pressure feed water with the highest pressure level of the HRSG. The disclosure further refers to a method for operating a CCPP with such a fuel preheater.