This report is structured as follows. First, there is an introduction that describes the district heating legitimacy in the community. Next comes the problem analysis describing the variations of the district heating system and a description of the individual parameters, finishing with a short description of the water hammer that provide noise nuisance for consumers.
This leads to the problem statement: How can a control strategy be developed and how does it look when its purpose is to eliminate the noise pollution by homeowners as a result of water hammer in the pipes due to the start-up of the pumps?
In problem solving, a model based on an experimental measurement is developed.
This yield:
e(t)=10*e^(-t)
The model leads to the open-loop control and closed-loop control.
Two open-loop control strategies are developed. The best is the one with input from a Signal Builder. This regulatory approach meets both design criteria, namely that the rise time must be 135 s, and the overshoot should not exceed 5%. In addition, a closed-loop control strategy is developed. This fitted PI controller does not meet the design criteria with a rise time of 135 s. The Discussing seeks to optimize the model with PI controller by inserting a ramp limitation in two different locations in the model. But contrary to expectation ramp limitation tends to make the system faster.
In the discussion it becomes clear that the best strategy is open-loop control with Signal Builder, but this is not directly implementable at Aalborg Supply, Heating. It would therefore be interesting in cooperation with Aalborg Supply, Heat to find a way to implement an input equivalent to that provided by the Signal Builder.