Steam storage systems for flexible biomass CHP plants - Evaluation and initial model based calculation

Within the present study a novel concept for the demand-oriented power generation of a solid-biomass fueled combined heat and power (CHP) plant is investigated. The integration of a novel steam storage system into the plants process enables a decoupling of the steam (boiler) and the power generation (steam turbine). By buffering the steam, the power output of the turbine can be adjusted without changing the rated thermal capacity of the plant. The storage system consist of combination of steam accumulator and concrete storage. An initial model based simulation study is performed to identify the fundamental behavior of this system, integrated in a biomass CHP plant. The operation principle has proved their technical feasibility and seems to be applicable at a commercial scale. According to the modelling results flexible short term power generation in a time range from 15 min to several hours is applicable. A load-range of almost the plant's rated capacity can be achieved. The properties of the proposed concept are competitive to available energy storage systems.