Staged control of domestic hot water storage tanks to support district heating efficiency

Storage tanks are commonly used for domestic hot water (DHW) preparation in large buildings supplied by district heating (DH), especially to cope with peak demand. The charging control of DHW tank systems is often suboptimal, increasing return temperatures and harming the overall DH operation efficiency. This paper presents two novel concepts optimize charging, satisfying comfort hygienic requirements without leading excessive flows. first, more complex concept employs smart energy meter sometimes billing. It inspired development a second, broadly implementable employing staged proportional gain an added temperature sensor. authors tested refined this staged-gain using validated Modelica model real system Danish multistory residential building. subsequently implemented field, successfully reducing energy-weighted 7 °C total flow 23.6% compared conventional thermostatic control. analysis accounted variation tapping, temperature, supply cold temperature. Furthermore, performance was robust relaxed settings valve constraints, demonstrating minimal configuration new implementations.