Master's Thesis Mathias Linden


Analysis and use of simulation models in the simulation of city districts

Due to the constant expansion of renewable energy in recent years, the proportion of electricity production,
which is not determined by the demand, but by the environmental conditions, increases.
To compensate for the resulting difference between the generation and the demand of electrical
power, it will be necessary to temporarily store electricity or shift the usage of electric power. Hot
water tanks can be used for this task by regulating combined heat and power (CHP) systems and
heat pumps not with regard to the heat demand, but according to the current demand of electric
power. The surplus of heat can be stored in hot water tanks. To evaluate the potential of this approach,
simulations of, for example, city districts, are necessary.
This master thesis deals with components of these simulations. Different radiator models, different
ways to include domestic hot water (DHW) profiles and, in particular, the used hot water storage
tank model are analyzed. To evaluate the hot water storage tank model, experiments are carried out
including real hot water storage tanks of different size. Subsequently, in order to investigate the interaction
of the parameters found, several different models of houses, which include the considered
components, are simulated with the parameters previously determined.
It turns out, that the hot water storage tank model reproduces a loading cycle well, if it is correctly
parameterized. Simple cooling processes, however, are reproduced poorly, due to the fact, that the
hot water storage model is one-dimensional and does not consider the buoyancy. Limiting the maximum
interval length of the solver used in the simulation turns out to be useful, too, in order to
achieve better results in terms of including DHW profiles (or other tables).