电力工程技术 (Jan 2023)
Simulation of temperature field and current carrying capacity of direct buried XLPE cables under different laying conditions
Abstract
Soil direct burial is widely used for laying power cables because of its advantages of short construction period and good heat dissipation performance. During the burial process, various laying conditions have an important impact on the temperature rise and load capacity of the cable. In this paper, in order to investigate the influences of various laying conditions such as backfilling sand, adding concrete protection plates and installing sleeves on the temperature field and load capacity of direct buried cables, Comsol finite element simulation software is applied and electromagnetic field, thermal field and fluid field are modeled on 110 kV cross-linked polyethylene (XLPE) power cables. The results show that backfilling with sand increases the cable load capacity, and the increase of the cable load capacity slows down with the increase of the backfilling thickness. The adding concrete protection plate has less effect on the load capacity, and the increase of the load capacity is less than 0.5% compared with that without the cover. The filling high thermal conductivity material in the drainage tube increases the cable load capacity, and the increase of the load capacity is higher than 50% when all three phases are filled with high thermal conductivity material and the middle phase is filled with high thermal conductivity material compared with the case without the filling. Compared with the case of no filling, the increase of load capacity when all three phases are filled with high thermal conductivity material, the middle phase is filled with high thermal conductivity material, and the other two phases are filled with low thermal conductivity material is higher than 50%. When the above factors are considered at the same time, it is favorable to the increase of cable load capacity.
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