Stochastisch-heuristische Prozessgütebewertung foulingkritischer Kesselsysteme

This work develops and tests a stochastic–heuristic method for assessing the process quality of boiler systems used in energy conversion from heterogeneous fuels (in particular waste and bio-mass). The approach combines an internal, inverse thermodynamic boiler balance with an external, data-driven state estimation, explicitly addressing underdetermination, measurement uncertainty, and the verification of stationary operating phases. Methodologically, classical mass and energy balances are coupled with optimization algorithms (including Nelder–Mead); measurement data are standardized, confidence-checked, and processed in a two-layer evaluation framework. In the research context, the thesis systematically situates calorific value determination and plant balancing of energy generation systems—especially waste incineration plants (e.g., Behrendt; Morf/Brunner; Reimann, Pohl)—highlighting strengths and limitations of indirect calorific value es-timation based on plant parameters and inverse combustion calculations, and demonstrating the need for robust, detailed methods. The proposed method is validated on a northern German waste incineration plant. The application shows that reliable information on boiler condition, heat surface fouling, residence times (according to the 17th BImSchV), and plant-specific performance indicators can be derived from continuous operational data. At the same time, systematic deviations (e.g., in flue gas flow rates) are identi-fied, whose knowledge improves the reliability of state diagnostics. The central contribution is a practical coupling of balancing and optimization, enabling the determi-nation of critical parameters—previously known only approximately—such as the current calorific value of unknown fuels, directly from process data. This supports transparent evaluation and oper-ational optimization. Limitations arise from the availability and quality of certain measurements and from the handling of inhomogeneous fuels; the work demonstrates how these limitations can be methodically addressed and turned into opportunities for future applications.