Thermo-hydraulic coupled modelling: Analysis of thermal enhanced backfill structures and materials for near-shore power cables

摘要

Offshore wind power has been an expanding market during the last decade. The wind powerrnstations are electrically connected via buried high voltage cable systems. Due to the electrical resistance of cables,rnthermal energy is emitted during current transport. The emitted heat damages and ages the cable, and weakenrnsignificantly the cable’s performance. A thermal enhanced backfill embedding the cable helps distributing thernproduced heat fast to the surrounding soil and protect the cable from excessive heating.Thermo-hydraulic coupledrnsimulations have been carried out to analyse the influence of thermal enhanced backfill on the temperaturerndistribution around these high voltage cables. A comparative study with different thermal backfill materialsrnembedding a high voltage cable was performed, in order to identify suitable thermal backfill properties and itsrnarrangement around the cable. For this purpose, three different numerical solutions have been used (OpenGeoSys,rnCOMSOL, FEFLOW). The results show that heat distribution around high voltage cables is strongly influencedrnby thermal and hydraulic properties of the surrounding backfill and that a proper backfill is able to modify thernheat dispersion according to requirements.