The modern steam turbine (ST) in a combined cycle power plant makes 50% of its power from the low pressure (LP) section, making the selection of the LP turbine one of the key drivers in the overall efficiency and output of the plant. A variety of inputs drive the selection of the LP turbine, fundamentally driven by the total exhaust energy out of the gas turbine(s) and the ST backpressure that can be achieved at site. Contemporary offerings of last stage blade (LSB) sizes enable the OEM to select multiple options for the LP turbine configuration, for example, a single large LSB in a single flow LP configuration, or a smaller LSB in a two flow LP configuration, the analysis can be extended to a two flow versus a four flow configuration as well.
In addition to key value tradeoffs, the conversation will also focus on benefits of the underlying technology that was chosen for GE’s ST portfolio from GE’s acquisition of Alstom. From here synergizing technologies will be focused on items such as integration of the last stage blade (LSB) portfolio, sealing technology and aerodynamic technology for high pressure and intermediate pressure section blading.
In conclusion, it will be shown how GE’s ST portfolio will enable the power industry to achieve higher efficiencies, and reliability while responding to the ever-increasing load cycling demands of today’s modern gird.