Load flexibility is partly concerned with high partial load efficiencies and partly with the load cycle behaviour, i.e. with the realisation of quicker load changes, including quick ramping up and down processes. High partial load efficiencies are principally concerned with the aerodynamics of compressors, i.e. using increasingly complex calculation processes, compressors are being designed so that they remain stable in a wide working range while nevertheless maintaining a high efficiency. By using improved calculation processes, the load cycle behaviour is being studied to gain a better understanding of how the thermally determined unequal temperature distributions in the gas turbine housing and rotors affect their expansion and service life. This will then be used to improve their design.
The image shows a steam turbine for a solar-thermal power plant in Spain. The requirements for steam turbines are highly specific: it must be possible to ramp them up very quickly when the sun rises in the morning and they must be able to adapt to fluctuating heat outputs during the day, such as for example if clouds draw across. ©Siemens
