Low-‎computational adaptive MPC algorithmization strategy for over ‎and ‎undershoots ‎instantaneous ‎water ‎heaters stability

Abstract

Tankless gas hot water users' perceived comfort is severely affected by sudden changes deviating from the desired temperature. Water temperature instability due to overshoots and undershoots is the most common issue that appears mainly due to sudden changes in users' water flow demands and response delays inherent to the heating system. Classical controllers for heat cells have difficulties responding to temperature instability in a timely manner because they lack the capacity to anticipate the effects of sudden variations in water flow rate. Previous studies have reported the model predictive controller (MPC) with adaptive function strategy to provide the best response for stabilizing temperature, and its performance is a result of the predictive nature that allows for anticipating and correcting the negative effects on temperature from sudden flow rate variations. The present study aims to employ this strategy to a low-computational algorithm that can be embedded in low-cost hardware with limited computational and memory resources. The study's motivation is to fill the space manufacturers have left in this regard by implementing low-cost optimal-performance microcontrollers for water heaters. The algorithm results show good agreement for the responses in temperature stabilization with experimental data.