Mathematical Model of Soot Blowing Influences in Dynamic Power Plant Modelling

Abstract

Due to the increasing integration of renewable energy sources in the existing power grid the conventional power plants have to set their focus more on flexibility and grid stabilization than supplying the base load. Since this task was not foreseeable when designing the currently existing power plants, they will have to suffer completely different load scenarios than expected. Dynamic modelling of complete steam cycles is a promising way to study the power plant operation of various future scenarios. To adapt the model to real power plant behaviour, especially with a focus on control events, the implementation of effects due to steam blown into the gasside part of the boiler in order to detach soot from the heating surfaces (soot blowing) seem to bring great efforts concerning model validity. Furthermore special control optimizations can be done, for example on spray injection at soot blowing events. In this study temperature measurement data is used in combination with a highly detailed boiler model of a 550 MW hard coal fired power plant to build a mathematical model of soot blowing influence on the different heat exchangers.

Evaluation of the effects of a load shedding at a lignite power plant

“…To this end, various measures are tested and optimized in dynamic models prior to testing in the power plant. These include improvements for the supply of control power, as can be seen in Refs [16, 19–22] improvement of the start‐up process, 23,24 and the reduction of the minimum power 25,26 . In addition, as 27 shows, dynamic models can be used for analysis in case of changes in the power plant infrastructure, for example in the integration of thermal storages.…”

Applying the Power Plant Library ClaRa for Control Optimisation

“…An effect of the soot blowing on the fouling coefficient, which is a parameter that reduces the heat transfer to the heating surfaces, is not considered. An approach to model variable fouling factors which are affected by soot blowing is presented in (Gierow et al, 2015). This simplification is acceptable since the focus of the investigation is on the short-term energy and mass transfer of steam and water from the water steam cycle to the furnace and its impact on the control performance of the power plant.…”