Project Leader:	Professor Dr-Ing Otto Geisler
Research Assistant:	Dipl-Ing H Henke
Duration:	01.01.1994 - 31.12.1996

For the supply of communities with combined gas and steam turbine district heating plants the interaction between the plant units and the secondary side of the district network must be optimised.

During commissioning of a new gas and steam plant an extensive collection of measurements was made in-situ, in collaboration with the site management. To enable from start a reliable basis for evaluating the condition of the plant and its components it is important to introduce a fast computer-based monitoring of all parameters which are relevant with the safety and the cost efficiency of the plant.  A key aspect is the analysis of the dynamic behaviour of district heating plants under varying operating conditions, considering that especially plants with extraction condensing steam turbines can adapt very well to varying power and heating loads.

In a second project phase the system behaviour of the secondary side of the district network was studied. Influencing technical factors here are the performance maps of the district network pumps as well as the operating curves of the heat exchangers and the piping. Thermal and hydraulic fluctuations in the operating conditions of the network must be taken into account through the resulting changes in pressure and heating loads. Special emphasis was given to the interconnections between individual district heating networks.

From these system analyses it was possible to define interventions enhancing the safe and cost effective operation of the whole district heating systems.