Short-term Optimization of the Operation of the CHP District Heating Plant with Heat Accumulator

In this work, the operating cost of the CHP production is reduced by creating optimization model to schedule the operation of the heat storage. The objective function of the model targets to minimize heat production costs and maximize profits of electricity production. To implement the optimization model in practice and automate the operation, the heat storage operation in every normal production situation of the CHP production with its real-life process constraints is modelled. To model the time-variant and non-linear system detailed enough, a MILP (Mixed Integer Linear Programming) model was selected and used to create a piecewise linear model of the system. A sliding time window method was used in the optimization to enable the most optimal heat storage operation in practice. The output of the optimization model is the operation plan of a heat storage for the next day, which provides the smallest operating cost for CHP production. The model can be also applied for heat storage investment planning.