Dynamisches Verhalten von Abnehmeranlagen bei instationären Strömungsvorgängen in Fernwärmenetzen

In district heating networks there are numerous consumer installations whose house service connections are partly directly and partly indirectly connected to the network. With both types of connection the pressure and flow rate are usually regulated at the consumer installation, whereby medium-controlled regulating devices are used predominantly. Here one differentiates between variants such as the regulation of the outflow pressure, the regulation of the differential pressure, regulation via a short circuit line or various combinations of these types of regulation. The regulation installations react to changes of state in the network and therefore they in turn have an effect on the network. This dynamic interplay of the consumer installations with the network was investigated in a research project. On the basis of measurements various influential parameters of the network and of consumer installations on the dynamic processes were determined. It was shown that the time behaviour of the regulating installations and thus the regulating speed form the principal influential factor on the hydraulic processes in the network. For the numerical calculation of the dynamic interplay between the installations and the pipe network, a model for the consumer installations, which shows the characteristic dynamic behaviour, was developed and implemented in a program for intermittent flow currents. In this model the correct portrayal of the regulation devices and their time behaviour are of significance. Calculations using this model show that the measurements obtained can be very well reproduced