Research on low-carbon district heating system planning approach based on thermal energy grade and integrated demand response

Abstract

Low-carbon district heating systems are the result of the improvement of existing fossil-based district heating systems, where various environmentally friendly heat sources are integrated to decarbonize the heating sector. Existing research has the problem of emphasizing “quantity” over “quality” in the planning stage of the district heating system and does not consider the load elasticity of the demand side, resulting in redundancy in the equipment capacity. Therefore, a source–load–storage collaborative planning approach for a low-carbon district heating system is proposed, which comprehensively considers the grade equivalence of thermal energy supply and demand, and integrated electricity-heat demand response to achieve the optimal system configuration. Additionally, we establish a refined mathematical model of latent heat thermal energy storage based on engineering-measured data to address the issue that a general energy storage planning model cannot accurately describe the differentiated charging–discharging characteristics of multi-energy storage systems. A case study is considered, and the results are thoroughly analyzed. Compared to the conventional planning method, the proposed method can effectively reduce the capacity of system equipment by up to 35.0% and reduce the annual investment cost by approximately 5.31%. The outcomes can be referred to for district heating system planning decisions.