The proposed method is validated in several test cases using experimental data from a plant in Nyköping. The optimizations demonstrate the feasibility and the high economic potential of the proposed approach when comparing with measurement data and the standard optimization techniques. The optimized planning schedules result in a balance between produced and consumed heat; priority to low-cost boilers and maximization plant revenue. Compared to measurement data; the optimizations result in a significantly lower supply temperature; a more extensive usage of the external cooler for higher efficiency and higher electricity production; fewer starts of units as well as an appropriate use of the accumulator tank.
The high-level description of optimization problems using JModelica.org provides useful means to specify flexible optimization problems including con-straints on arbitrary process variables such as heat load of the production units; supply temperature and flow rate; pressures.
Keywords: Production planning; nonlinear optimization; district heating; physical modeling; unit commitment
Proceedings of the 10th International Modelica Conference; March 10-12; 2014; Lund; Sweden
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