The Gas Turbine GT26 in Combined Cycle Application: Conversion of a Coal Power Plant Into a Modern Combined Cycle Firing Natural Gas and Oil No. 2

The current paper describes the repowering of an existing coal plant (Rheinhafen Power Station). In this power plant, the hard coat boiler was repleced by a modern once through, Heat Recovery Steam Generator (HRSG). The HRSG is connected to a natural gas or oil fired gas turbine ABB GT26. The plant is located in Karlsruhe, Germany, and is operated by the Badenwerk AG, a public utility. The original hard coal fired plant was put into service in 1964. It is equipped with a steam turbine of approx. 100 MW power output. To maintain the initial steam data of the power plant at 160 bar and 540 °C, and to guarantee a low start-up time, an unfired once through type steam generator was chosen. Minor modifications were done in the steam turbine to increase the maximum steam turbine power output to approx. 124 MW. Combined with the approx. 240 MW power output of the GT26 a total output of 363.5 MW. MW is expected. The efficiency has thus been increased from 38 % for the steam power plant to 58.2% for the combined cycle.