Optimization modeling for smart operation of multi-source district heating with distributed variable-speed pumps

Smart district heating integrated various advanced technologies to implement the motivation structures and minimum operation cost. In this paper, an exact mathematical model has developed to describe the thermal and hydraulic characteristics of a district heating system which applied the distributed variable-speed pumps. Afterwards, two associate optimization models have been established and the relevant regulation methods have been introduced to fulfill all customers' heat demands with less operation cost and more rapid regulation response. The proposed two co-operative approaches, which mean “coarse tuning” and “fine tuning”, have been then performed in a district heating system in Dezhou, China as a case study. Results indicate that the economical operating and less response time can be achieved simultaneously when the two proposed approaches are combined together. In contrast to the conventional approach, the total operation costs decreased by 4.99%, 11.39%, and 22.73%, respectively, in the concerned three scenarios. Moreover, the heat losses of the heating scheme can be decreased of 12.72%, 9.73%, and 4.47% at the same time. The results obviously demonstrate the great advantages and potentials of this smart operation approaches in the practical application.