Development of ANN model for geothermal district heating system and a novel PID-based control strategy

This article refers to development of ANN modeling for geothermal district heating systems, and the novel and optimal control strategy for exergy efficiency maximization by using these systems. As a real case study, the geothermal district heating system in Afyonkarahisar (AGDHS), Turkey is considered. Its actual thermal data as of average weekly data are collected in heating seasons during the period 2006–2010 for ANN model and control strategy. In this study, a novel control strategy-based PID controller is proposed to ensure the maximum exergy efficiency via the flow rate control of the AGDHS. ANN model of the AGDHS is used as a test system to demonstrate the effectiveness of the proposed control strategy under various operating conditions. The results of this study show that the network yields a good statistical performance with respect to maximum correlation coefficient (0.9986) with minimum RMSE and MAPE values. Moreover, the proposed PID controller has better control performance compared to the manual control even in the presence of the AGDHS. Energy efficiency and cost saving of the system are increased by 13% by the proposed control strategy. Thus, the proposed control strategy has the potential for creating more comfortable thermal environments for district heating systems.