Control of double-heater heating systems for the efficient energy supply in heat distribution networks

This work deals with the problem of lacking heating system flexibility that reduces the energy efficiency of the whole heat distribution network and increases its operating costs. Therefore, in the paper, a systematic design and tuning of the dedicated control system for double-heater heating systems are proposed. First, the connection of two heaters in a series allows for high flexibility of the whole heating system in terms of dynamical properties. For this configuration, the dedicated control system is introduced based on the cooperation of the conventional PI (proportional-integral) and integral controllers. Then, it is proposed to further improve its performance by adding a custom and universal feedforward compensator. For both proposed approaches, a robustness analysis is performed followed by a realistic MATLAB-based simulation verification and experimental validation based on PLC (programmable logic controllers) implementation. The proposed approaches significantly improve the efficiency of the energy supply compared to conventional single-heater heating systems. The locally produced results show quantitative improvements between the proposed frameworks, which, in selected instances, reach between 40.9% and 85%, according to the user-defined quality criterion.