Comprehensive Performance Assessment of an Integrated Energy System Involving Heating Power Energy Tunnels and Solar Energy

To address the issues related to the intermittent and unstable nature of solar energy as well as promote the overall efficiency of heating power tunnels, an integrated energy system for both space heating and domestic hot water supply has been constructed. A thermal model of crucial equipment is established, focusing on heat collection, storage, and transfer. The required areas of photovoltaic and concentrated photovoltaic thermal components, as well as the capacity of the thermal energy storage tank, are calculated using the nondominated sorting genetic algorithm-II in conjunction with the Designer’s Simulation Toolkit (DeST) simulation software. These calculations are conducted under the initial constraints of meteorological conditions in Beijing and the designed annual cumulative heat load. From the indicators of economy, energy, and environment, i.e., the annual cost saving ratio (CSR), the primary energy saving ratio (PESR), and the carbon dioxide emission reduction ratio (CO2ERR), the capacity allocation of this system is optimized and the system performances are evaluated. The results show that compared with the reference system, CSR of the integrated system increases by 9.62%, PESR increases by 85.56%, and CO2ERR reaches 62.42%. This system not only guarantees the heat supply for space heating and domestic hot water for buildings along the route, but also promotes the utilization of solar energy and achieves the cooling of heating power tunnels to maintain underground thermal balance, providing a valuable reference for sustainable architectural design.