Investigation on Improving the Ampacity of Power Cables within Tunnel Through the Application of Heat Pipes

Tunnel laying is a common cable laying way. However, the ineffective heat transfer between cables and air in the tunnel will lead to a severe restriction on the cable's ampacity. Applying heat pipes can be an effective method to solve the issue. In this paper, the simulation model of tunnel laying cables was used to verify the overheating issues. Then, the simulation model for cable laid in tunnel considering forced air-cooling method was established, the improvement effect of forced air-cooling method on the ampacity of cable was discussed by using the proposed simulation model. The simulation results show that forced air-cooling is hard to completely solve the overheating problem in the tunnel. Therefore, the heat dissipation method involving heat pipes was proposed. The working effect of the heat pipes was verified by simulation. The investigations in this paper show that the use of heat pipes can have a great contribution to ensure the efficient operation of cables in tunnel.