Integrated heat and power optimal dispatch method considering the district heating networks flow rate regulation for wind power accommodation

Wind curtailment has been severe in northeast China since the “heat-led” operation mode of the coal-fired combined heat and power (CHP) units restrains the flexibility of the power systems. District heating networks (DHN), which owns the thermal inertia, can be integrated into the power dispatch to increase the heat output of the CHP units ahead of midnights and to reduce the CHP's heat and power output at midnights, thus improving the wind power accommodation. However, almost all the integrated heat and power dispatch models ignored DHN flow rate regulation, which is a significant method to influence thermal inertia as well as the users' thermal comfort. Thus, this paper proposes a new approach to improving wind power accommodation by integrating the DHN flow rate regulation into the power dispatch. Results show that the wind power accommodation increases with the increasing flow rate due to the increasing thermal inertia. The wind power curtailment at a flow rate of 1.0 m∙s⁻¹ decreases by 5.5% compared to that at 0.5 m∙s⁻¹. However, the flow rate cannot be too high because fairly high electricity consumption of water pumps would become the main reason for improving wind power accommodation, which is meaningless.