Configuration Strategy and Applicability of a District Heating Peak-Shaving System Based on Cross-Seasonal Borehole Thermal Energy Storage
Industrial waste heat district heating systems face a mismatch between constant heat supply and seasonal demand, requiring peak-shaving capacity expansion. This study proposes a peak-shaving system integrating cross-seasonal borehole thermal energy storage (BTES), absorption heat pumps, and biomass boilers. Using outdoor temperature data from Shenyang, a dynamic heating load model was constructed to quantify peak-shaving demand and determine BTES layout. An absorption heat pump raises the borehole return water temperature to increase the BTES contribution. The optimal configuration was identified, and the annual cost method was used for economic evaluation. Results show that under the optimal configuration, 630 boreholes are required, with the BTES contributing 40.4% of the total peak-shaving heat demand. The total peak-shaving heat for a typical heating season is 2.3×10⁴ GJ, with a peak-shaving duration of 1845 h, meeting a maximum peak-shaving power demand of 12.4 MW. The annual cost per unit of extracted heat for cross-seasonal peak-shaving is 34% lower than that of a ground source heat pump system, demonstrating significant economic viability. This system offers an efficient, low-carbon solution for district heating peak-shaving in severe cold regions.