Simulation and optimization research of coupled heating system using data center waste heat and solar energy based on seasonal soil heat storage

A coupled heating system using data center waste heat and solar energy based on seasonal soil heat storage is proposed in this paper. During non-heating season, the coupled heating system stores waste heat from data centers and solar energy in the soil. In the heating season, the system utilizes waste heat from data centers, solar energy, and ground source heat pumps for combined heating. Due to the incorporation of data center waste heat, this coupled heating system is suitable for mid-to-high-rise residential buildings with limited area for solar collectors. To verify the feasibility of the system, this study focuses on 20 ten-story residential buildings and performs an in-depth analysis of the coupled heating system. During the 10-year operation of the system, the average soil temperature increases annually, with a total rise of 0.60 °C. As a result of the gradual increase in soil temperature, the system energy consumption decreases from an initial 3.49 × 10⁶ kWh to 3.42 × 10⁶ kWh, while the COP improves from 4.08 to 4.17. This indicates that the coupled heating system can fully meet the heating demands of mid-to high-rise buildings. Finally, the sensitive variables are used as optimization variables, with the annual cost as the objective function, to perform the economic optimization of the coupled heating system. The result shows that after optimization, the overall cost of the system is reduced by 3.4 %, and the COP of the system improves by approximately 5.7 %.