LAUSR

Abstract Taking wind direction and flow separation into account, the circumferential temperature difference of cable laid in forced-ventilation tunnel is investigated. Combining the heat conduction, the convection and the radiation, the formula calculating the thermal resistance is derived, followed by cable thermal network model in tunnel. The circumferential heat transfer and temperature profile for tunnel cable is analyzed. The results indicate that the temperature of cable is not only transmitted radially, but also circumferentially. The temperature on the leeward side is higher than that on the windward side. As the load increases, the circumferential temperature difference rises. The larger the wind direction angle, the smaller the temperature difference. When the angle is greater than 40°, continue to increase the angle does not have a great impact on the heat dissipation and temperature difference. It suggests that the temperature calculated by IEC-60287 is conservative as it does not take account of multi-factor interactions. The transient thermal network is also established.