Preprint 04-2015

The Honigmann Process - a mathematical study

Author(s) : Ann-Kristin Baum , Lia Strenge

Preprint series of the Institute of Mathematics, Technische Universität Berlin
Preprint 04-2015

MSC 2000

34A09 Implicit equations, differential-algebraic equations

65L80 Methods for differential-algebraic equations

Abstract :
The Honigmann process is a thermochemical energy storage converting low temperature heat into mechanical work. To control and optimize the operation of the storage, the Honigmann process is simulated numerically using a set of differential-algebraic equations (DAEs) as governing equations. We analyze this DAE regarding its solvability, the uniqueness of solutions and the efficiency of numerical solvers. We identify the steps of the process modeled by a reliable, uniquely solvable mathematical model and point out those steps, where the mathematical model may lead to ambiguous solutions. For the steps of the process described by a uniquely solvable model, we compare several numerical solvers with respect to efficiency and accuracy.

Keywords : Thermochemical Energy Storage, Honigmann Process, Strangeness Index, Differential-Algebraic Equations