Integrated heat and power dispatch truly utilizing thermal inertia of district heating network for wind power integration

Abstract

Utilizing the thermal inertia of a district heating network (DHN) for thermal storage is considered an effective energy-saving method for improving the operational flexibility of combined heat and power (CHP) generation units for wind power integration in an integrated heat and power dispatch (IHPD) system. However, to truly utilize the thermal inertia of the DHN, the supply and return temperatures at the heat source are both necessary to regulate the district heating system (DHS) for wind power integration, whereas the heat output of CHP is not able to do that. Therefore, a new IHPD model that considers the thermal inertia of the DHN was formulated to improve the flexibility of CHP units for wind power integration, in which the first proposed integration model was used to completely simulate the dynamic temperature distribution of the DHS. The optimised supply and return temperatures at the heat source were then obtained to guide the operation regulation of DHS for wind power integration in actual engineering applications. Moreover, the stored thermal energy and the thermal storage rate of the DHN were quantitatively calculated to determine the thermal state of DHN. To analyse the effects of the proposed IHPD model, the approach was compared with a conventional heat and power dispatch model through a case study based on a real DHS. The results demonstrate the advantages of the proposed model in terms of wind power integration, energy saving and operation regulation of DHS.