Primary frequency regulation capacity enhancement of CHP units: Control strategy combining high pressure valve adjustment and heating extraction steam adjustment

Flexibility provision by combined heat and power plants – An evaluation of benefits from a plant and system perspective

“…Previous works have investigated strategies to increase the flexibility of CHP plants (mainly coal and natural gas-fired plants) and evaluated the profitability of flexibility measures on a plant level. Table 1 provides an overview of main outcomes from studies that investigate plant-level flexibility measures, including turbine bypasses [28][29][30], a variable power-to-heat ratio [28,30,31], thermal energy storage (TES) [28,29,[32][33][34][35], coordination with electric boilers [29,32,33,36], steam extraction regulation [37,38], steam storage systems [39,40], thermal buffers [41], disconnection of the low-pressure turbine section [29,32,42], and control systems for improved operational flexibility (e. g., cycling and ramp rates) [43][44][45]. The cited studies demonstrate that there are several ways to enhance the technical potential for CHP plant flexibility, that might increase the plant revenue.…”