Insulated Steel Pipes for District Heating Networks
2025-08-08
The purpose of insulating heating pipes is to reduce heat loss during the transportation of the heat medium, save energy, and improve the economic efficiency and performance of the system operation.
The purpose of insulating heating pipelines is to reduce heat loss of the heat medium during transportation, save energy, and improve the economic efficiency and performance of the system operation. The role of the insulation layer is to reduce energy loss, save energy, improve economic benefits, ensure the operating parameters of the medium, and meet the production and living requirements of users. For insulation layers of high-temperature medium pipelines, it can also lower the surface temperature of the insulation layer, improve environmental working conditions, and prevent scalding accidents; the protective layer serves to protect the insulation layer from external mechanical damage.
The insulation structure mainly consists of three parts: the first layer is the spiral pipe body; the second layer is the insulation layer, which uses polyurethane foam plastic; the third layer is the protective shell, made of high-density polyethylene or fiberglass.
Anti-rust layer: This refers to the anti-rust primer applied on the surface of pipes and equipment after rust removal, generally applied 1-2 times.
Insulation layer: This is the main layer that reduces energy loss and provides insulation, attached outside the anti-rust layer.
Protective layer: It protects the moisture-proof layer and insulation layer from external mechanical damage. The material of the protective layer should have high mechanical strength, commonly made from asbestos gypsum, asbestos cement, fiberglass cloth, plastic film, metal sheets, etc.
The thickness of the insulation layer can be determined based on the thermal calculation of heating pipeline insulation. The thicker the determined insulation layer, the smaller the pipeline heat loss and the more fuel is saved; however, increasing thickness raises the cost of the insulation structure and investment expenses. In engineering design, the insulation layer thickness is determined based on the thermal calculation of pipeline insulation and the "economic insulation thickness" derived from techno-economic analysis.
