Review of insulation design methods for directly buried pipelines in solar heating systems

This paper provides a comprehensive review of insulation design advancements for directly buried heating pipelines and their current application in plateau solar heating systems. Drawing upon relevant literature and standards, it synthesizes research findings pertaining to pipeline heat loss calculation, operational efficiency assessment, and insulation layer thickness design. Firstly, the paper examines methods and advancements in calculating heat loss in heating pipelines, considering both steady-state and unsteady-state conditions. Secondly, the insulation design of heating pipeline is divided into economic and alternative insulation methods based on operational evaluations, and the key design points are summarized. Thirdly, this paper elucidates the evolution of solar heating systems in plateau regions and identifies shortcomings in insulation designs for directly buried heating pipelines in these areas. Finally, this research focuses on the insulation design of directly buried pipelines in solar heating systems situated on the Qinghai-Xizang Plateau. It emphasizes the exploration of innovative methods and technologies aimed at minimizing transmission and distribution losses within the solar heating system network, while considering the unique climatic and geological condition characteristics of the plateau. This initiative aspires to promote a green and low-carbon transformation in China’s heating sector, steering it towards high-quality development.