Siemens Flex-Plant with Clean-Ramp

摘要

Conventional combined cycle power plant started slowly to enable the HRSG and steam turbine to warm up. With more renewable energy such as wind and solar coming on line, there is a greater need for combined cycle gas turbine (CCGT) facilities to start up more quickly and ramp at high rates to follow grid demand. To meet the need to make up for the potential generation short fall from renewable sources (i.e., wind and solar), new designs have been implemented which enable CCGT facilities to start up (or shut down) at a moment's notice, and ramp at a much higher rate (up or down) to follow grid demand. Old plants are trying to adapt, and new designs have become available with flexible features designed to meet these need needs. Siemens Flex-Plant combined cycles are now in operation, and have demonstrated the ability to startup much quicker and achievement of emissions compliance much faster than conventional CCGTs have been able to achieve in the past. The latest version of the Flex-Plant offers Siemens Clean-RampTM technology which enables these plants to stay in emissions compliance even when ramping frequently. The Clean-Ramp strategy includes forward feed control logic to improve response time, and a gas turbine (GT) tuning approach that aids in maintaining stack emissions compliance during ramping. This paper presents results showing the reductions in actual operating facility Flex-Plant startup emissions and times to emissions compliance. In addition, this paper presents the results of Clean-Ramp implemented at a Siemens Flex-Plant in California. During demonstration of Clean-Ramp at this facility, the GT was ramped continuously at ≥ 30 MW/min between approximately 115 MW to base load throughout the hour. The results show that stack NO_x, CO and NH_3 slip were all maintained at less than 2 ppmvd @ 15% O_2 during the entire hour.