Investigation on improving the asset utilization ratio of underground power transmission system through the application of heat pipe

The prevalent dense cable arrangement can lead to serious overheating problems due to the mutual thermal effects between cables, which will result in a low asset utilization ratio of underground power transmission system. However, there still lacks the effective countermeasures with maintenance-free, no-additional losses and high reliability. To address this issue, the auxiliary cooling method of densely laid cables by utilizing the heat pipe was proposed in this paper. Firstly, the methods of selection and arrangement of heat pipes were presented, then the cooling effect of applying the heat pipe was analyzed through simulation. Subsequently, the modified thermal model for cables with heat pipe-assisted cooling was built, and the solution algorithm for the model was proposed. The comparison of temperature results obtained from the simulation model and the modified thermal model was presented. The results show that the results obtained by the modified thermal model are in excellent agreement with those obtained by simulation model, and the maximum error does not exceed 3 °C. The application of heat pipes will significant significance for enhancing the transmission capacity of densely laid cable group. The methodology developed in this paper can be adapted for various densely laid cable scenarios with suitable modifications.