New technology and advanced software controls are changing the ability for gas plants to respond flexibly to demand and harness waste heat driving renewed profitability for operators. “As plant performance improvements are more and more often optimized through smarter software our solutions are increasingly focused on the integration of hardware and software across the plant,” Andreas Pickard from Siemens told Gas to Power Journal.
One such change has been Siemens Flex-Ramp concept which allows steam turbine output to be used to improve gas turbine ramp rate using new control logic. This solution provides performance improvement without the need for new hardware through new profiles for both ramp up and ramp down.
During ramp up, additional steam is produced from HRSG stored energy using open high- pressure bypass. This results in a high-pressure drop with immediate additional steam production and this additional steam is then routed to the intermediate-pressure steam turbine.
During ramp-down, load can be decreased faster due to precise control of the intermediate-pressure bypass station.
Lausward demonstrates record 85% fuel efficiency for gas
A test run of this technology in a commercial setting was presented earlier this year with the Fortuna unit, supplied by Siemens, at the Lausward CHP plant near the port of Düsseldorf showing record efficiency along with improved flexibility.
The plant’s use of Flexramp technology has allowed it to deliver up to 300 MW of heat for the district heating system achieving a record peak value for a power plant equipped with only one gas and steam turbine and a record overall fuel efficiency for natural gas as a fuel to 85%.
Gas plant future is tighter software integration
The ability to closely integrate software tools and analytics into gas power plants operations is driving the next wave of innovation.
“It is a few years since we changed our philosophy around gas power plants from pure baseload to more flexible operation with faster start-stop times. We are now in the process of refining this and fine-tuning,” Andreas Pickard explained. “This means intelligent software that can react faster and help to predict demands for a customer and advise on operating profiles based on market conditions, wear on components, price signals etc.”
Powered by Siemens Sinalytics platform the move towards digitalization is now reaching ‘tipping point’ as complete digital twins of entire power plant systems have increasingly become a necessity for both day to day operation and piloting of new lifecycle services.
“Two key issues we look at today are firstly automated conservation for plants that are frequently ramping up and down to prevent damages by corrosion; and secondly how to keep equipment warm during quiet periods to minimize life time consumption by thermal stress."