Reducing heat losses from aging district heating pipes by using cured-in-place pipe liners

Low heat losses from district heating (DH) networks significant for efficient energy utilization and carbon emission reduction. However, the additional heat loss due to the aging of DH pipes is a serious challenge. Usually, it needs to be solved by pipe refurbishment. The novelty of this paper is that a new strategy was proposed: using cured-in-place pipe (CIPP) liners. This strategy can realize pipe maintenance without pipe refurbishment and large excavations. It has advantages in economic and social cost. After that, a new CIPP liner with an enhanced insulation function was designed to support this strategy. The obtained CIPP liner exhibited a variety of advantages, including low thermal conductivity, high mechanical properties, low water absorption and high thermal stability. Finally, a numerical simulation verified the effectiveness of the liner. The effect of using CIPP liners was affected by the liner parameters and working conditions. Based on a set of parameters, the liner reduced the heat loss of the aged pipe by 55.4%. This work provides a new perspective for the maintenance of DH pipes and contributes to the energy conservation of DH networks.

Automated summary

A new strategy using cured-in-place pipe (CIPP) liners was proposed for the maintenance of district heating (DH) pipes, which can solve the problem of increased heat loss due to aging. A new CIPP liner with enhanced insulation function was designed and its effectiveness was verified through numerical simulation, reducing the heat loss of aged pipes by 55.4%. This work provides a new perspective for DH pipe maintenance and contributes to energy conservation.