摘要：The paper is an overview of selected ways of increasing the operational flexibility of steam units,which are predominant in the Polish power system.These studies were prompted by the dynamic changes in the structures of installed capacity and generation output in the National Power System due to a rapid increase in the number of wind turbines in the country.The methods of thermal unit operational flexibility improvement are divided into two groups.The first group comprises solutions with heat and mass storage as well as chemical energy storage.These are solutions to manage the auxiliary load of units regardless of system load.The second group consists of methods for an off-design increase in the safe level of thermal energy machine design stress.The development of numerical tools using complex methods of thermal stress determination,such as Burzyński-Pęcherski’s theory,combined with advanced on-line machine diagnostics,allows for an extension in the operational range of a machine,beyond the original safe operation limit without risk of damage or loss of service life,in other words.
