Since the twenty-first century, the demand for energy in the world continues to increase, and the contradiction between energy supply and demand is also deteriorating. Energy issues have become the key to restricting social development (Wang et al. in Energy Convers Manage 235, 2001), and countries are gradually paying more attention to energy conservation, new energy development and sustainable development (Xu et al. in Sustain Cities Soc 71, 2021; Zeng and He in Sustain Cities Soc, 2022). Because of the cold and cold climate conditions and the lack of energy in Northern Europe, the fourth-generation district heating system is mostly used in its district heating system. The fourth-generation district heating system has the advantages of reducing heat loss, improving heat production efficiency, and more efficient use of renewable energy. At present, the Nordic region and the experts who study district heating attach great importance to energy conservation work, so the energy consumption caused by heat loss of the fourth-generation district heating system has been focused on.