Hybrid storage solution steam-accumulator combined to concrete-block to save energy during startups of combined cycles

This work presents a novel steam accumulator and concrete-block storage system (SACSS) to recover part of the energy lost through cycle side during startups combined power plants (CCPPs). The accumulators are integrated with sensible-heat concrete provide superheated resulting then higher efficiency safer turbine operation compared systems based only on saturated steam. An economic analysis is performed considering two different scenarios: i) CCPP able execute fast using Benson-type heat recovery generator (HRSG) ii) operated conventional which employs typical drum-type HRSG. It worth mentioning that second scenario measured data. optimization SACSS carried out focusing in four design variables: number units, pressure, length outer diameter. optimum solution net present value 4.45 M€ payback period 3 years for suitable startups. For startups, 2.53 3.4 obtained. grows around 60 % both cases if benefits from carbon credits considered. In addition improvement, could be used preheat critical sections generators, reducing thermal stress fatigue damage Finally, emissions avoided thanks estimated 640 2 175 tons CO2 per year, startup cases, respectively.