Modelling and Simulation of Tube Register Storages for Process Heat Application

Kurzfassung

The master's thesis of the program ("Energy Systems") was completed at the German Aerospace Center, Deutsche Zentrum fuer Luft und Raumfahrt (DLR), Stuttgart, in the Department of Thermal Process Technology in the Institute of Technical Thermodynamics. To analyze thermal energy storages in Matlab R, a program was developed for the calculation of thermal tube register storages on the basis of existing Dymola models. The simulations are possible for latent heat storages using phase change materials and for sensible heat storages with concrete for example. To validate the model, measurement data was collected from the storage modules in Carboneras, Spain (DLR test facility). This test facility includes a two-part storage system, in which a phase change material storage is used for the two-phase evaporation and a concrete sensible storage is used for superheating steam. The storage modules were constructed for testing a storage system for direct steam generation. The test facility was errected at a conventional power plant of Endesa in Carboneras. In this thesis, the PCM evaporator storage model and the PCM two-part storage model with a preheater plus an evaporator are investigated. The objective of the program developed was to create a user friendly interface in the Graphical User Interface (GUI) environment in Matlab R for rapid dimensioning of tube register storages on the basis of a given performance prole. This performance prole is given by a matrix of time, temperature, mass flow rate, corresponding pressure and enthalpy. To get the needed storage size for dierent combinations of tube and n spacing, iterative loops were designed in which the tube and n spacing is varied. An inner loop is responsible for meeting the target conditions for the right storage size. The describted loop is realized and tested for PCM-tube register storages. It also gives a basis for dimensioning solid material storages and, nally also complete direct steam generation systems. The result will be available in the form of a matrix in the workspace of Matlab R and on the interface in the form of diagrams.