Bachelor's thesis Felix Stegemerten

 

Development of an automatic calibrator to determine the physical parameters for modular models of hydraulic systems

calibration methodology Copyright: EBC The three steps of the calibration methodology: one-time parameter reduction, multiple calibration and validation.

The optimization of building energy systems is an important sub-task for the achievement of the climate protection goals of the German Federal Government. Simulation models have established as an elementary tool for the further development and optimization of building energy systems. The parameterization of the models is of great importance for good simulation results.

One possibility to parameterize simulation models is calibration. In previous work, calibration was often carried out manually, which requires a great deal of time and experience of the system under consideration. The manual process is therefore mostly uneconomical.

In this thesis a calibration methodology for the automatic calibration of modular systems is developed. Using the modular approach, a process chain is described which reduces the effort and the required knowledge about the system to perform the calibrations.
The methodology is divided into three main steps. In the first step, the number of parameters for calibration is reduced. This process is particularly time-consuming in many of the work carried out so far and requires extensive knowledge of the modules. Due to the methodology presented, only a one-time parameter reduction is necessary for the modular models, since the results can be transferred to any other application. The reduced parameter set is then automatically calibrated. This process can be performed as often as desired with the results of the first step for different systems of the modular models. In the last step, the calibrated parameter values are validated to identify possible errors. If large deviations occur, a new execution of the methodology or the adaptation of the simulation model must be considered.

The presented calibration methodology is applied to modular models of the basic hydraulic circuits in connection with a heat exchanger. The measurement data required for calibration are recorded on an E.ON ERC test bench.
The simulation results after calibration show a very good fit with the measured data. Some curves describe minor deviations between simulation and measurement, but these are not due to the calibration methodology. The validation of the calibrated parameters also indicates a successful calibration.