Advanced Technology Single-Shaft Combined-Cycle Reference Power Plants for High Efficiency and Operating Flexibility

摘要

Today's challenge for the power generation industry worldwide is more than ever before to assure reliable and cost effective power supply, to minimize environmental impact and to prudently use existing fuel resources. Siemens Power Generation's proven single-shaft combined-cycle reference power plant program addresses these needs. In operation since the mid-1990s, these plants have demonstrated world-class thermal performance, plant availability and reliability. They also provide an additional advantage that is becoming increasingly more important, i.e. unparalleled operating flexibility by providing fast-start cycling capability. The single-shaft arrangement provides significant net efficiency improvement over the 1-on-1 multi-shaft alternate, with the application of a single, more efficient generator and lower auxiliary load requirements. This arrangement also results in a considerably smaller plant footprint. With the requirement for less electrical equipment, the single-shaft plant also provides a more cost-effective arrangement. To address the concern for operating flexibility, including fast start-up and shutdown capability, the single-shaft plant arrangement for the authors' company includes a center-positioning of the generator between the gas and the steam turbines with a clutch between the generator and the steam turbine. This results in lower start-up requirements, faster shutdown with earlier access to the gas turbine for maintenance and higher plant availability and reliability by providing the capability to operate the gas turbine without the steam turbine.