Real-time quantification for dynamic heat storage characteristic of district heating system and its application in dispatch of integrated energy system

Utilization of heat storage characteristic of district heating system (DHS) is promising to promote the flexibility of integrated energy system (IES). However, unlike battery with constant capacity, the capacity of DHS is related to heat storage/release rate and needs real-time quantification due to heat migration delay. This work proposes a novel quantification method combining system operation simulation and dichotomy method to evaluate the real-time heat storage characteristic of DHS, where such indicators as heat shifting capability, and available storage/ release capacity and depth are defined. Quantification results show that if DHS stores/releases heat rapidly for 1 h to reach the upper/lower capacity limits, the available utilization depth of storage/release process are only 52.65% and 57.60%, respectively, while a longer time duration of storage/release process will increase the available depth until reaching 100%. Then, based on the real-time quantification of DHS capacity, a scheduling strategy of IES is proposed by applying the rolling dispatch method. Comparison results show that the simpli-fication of constant heat storage characteristics of DHS brings the violation of system operation constraints, and the differences of dispatch results are up to 18.9% compared to those considering the dynamic heat storage characteristics of DHS precisely.