Model based engineering and control of latent heat thermal energy storage

Latent heat thermal energy storages (LHTES) have a high potential for significant improvements in plant performance. They allow for stabilization of energy flows and improved peak power and demand side management. For LHTES solid/liquid systems with industrial relevant phase change temperatures exceeding 80°C are of high interest. In practice, the full potential of LHTES is not exploited for two reasons. Firstly, the design and operation of LHTES is mostly carried out in view of quasi-static energy duties, rather than dynamic heat integration. Secondly, conventional control strategies are simple and restricted to fluid flow control for charging and discharging of the storage.

modELTES aims at developing LHTES models which can be applied in standard engineering and control software. For a suitable first principle model, multiple phenomena in the phase transition of melting and solidification need to be considered, e.g. a temperature hysteresis, kinetics in the phase transition, super-/ subcooling at solidification. The thermo-physical properties of the phase change materials (PCM) also show strong temperature dependency.

The outcome of modELTES is an improved physical understanding of the phenomena in the phase transition of PCM which is supported not only by experimental analysis but also by validated first principles models. Dynamic models will be experimentally validated and implemented in relevant software with simulation times at least two orders of magnitude faster than real-time.

To validate the computer aided design and control engineering approach, the LHTES models and software tools will be used in industrial projects for dynamic heat integration under variable load conditions with complex (parallel, serial, cascade) storage configurations and control structures.

Project start

April 2016

Project duration

24 months

Project partners

AIT Austrian Institute of Technology GmbH (Koordinator), Interdisciplinary Center for Scientific Computing (IWR), Ruprecht-Karls-Universität Heidelberg, VOIGT+WIPP Engineers GmbH

Funding line

3rd call, Bridge Frühphase, 2015

Links to publications

T. Barz, C. Zauner, D. Lager, D. C. López Cárdenas, F. Hengstberger, M. N. Cruz Bournazou, K. Marx: "Experimental Analysis and Numerical Modeling of a Shell and Tube Heat Storage Unit with Phase Change Materials"; Industrial & Engineering Chemistry Research, 55(29) (2016), S. 8154 - 8164.

T. Barz, C. Zauner, D. Lager, F. Hengstberger: "Modelling with experimental validation of a latent heat thermal energy storage for industrial high temperature applications"; Vortrag: 10th European Congress of Chemical Engineering, Nizza; 27.09.2015 - 01.10.2015.

AIT contact

Tilman Barz