There are significant differences in transmission delay and transmission loss between the heating network and the grid in the integrated energy system. This paper focuses on the effect of the heating network characteristics on the ultra-short-term scheduling of the system. Firstly

a heating network model for operational optimization of the system is established based on graph theory

in which the transient characteristics of heat medium temperature are studied emphatically. The formula for judging the transient/steady heat transfer characteristics of a pipeline is also derived according to the period of operation and the length of the pipeline. Then

the optimal operation state of the devices

the daily operation cost and the solution time of each model are compared among three situations(considering transient heat transfer characteristics

considering steady heat transfer characteristics only and ignoring the heat transfer characteristics of the heating network). Research result shows that the heat storage characteristics caused by the complex topology and transmission delay of the heating network have changed the matching mechanism between the supply and demand of the system thermal power. The supply thermal power at the heat source end and the demand thermal power at the load end are no longer matched in real time. Before and after considering the transient heat transfer characteristics of the heating network

the optimal output of the gas boiler changes significantly

the temperatures of supply water also vary greatly

all of which show that the transient heat transfer characteristics of the heating network should be considered in the ultra-short-term scheduling of the integrated energy system.