Underground cable crossing

QuickField simulation example

There are two single-phase cables crossing underground at different levels. Similar cable construction simulated in High voltage cable ampacity example.

Problem Type
3D problem of heat transfer.

Geometry

Given
Rated current: 1 kA
Aluminum conductor Joule heating power: 21.4 W per 1 meter of length.
Copper shield Joule heating power: 24.5 W per 1 meter of length.
Thermal conductivity of soil: 0.63 W/(m·K);
Thermal conductivity of aluminum: 200 W/(m·K);
Thermal conductivity of copper: 380 W/(m·K);
Ambient air: temperature T = 20°C, convection coefficient 10 W/K-m²,

Task
Calculate the temperature profile in the soil and cable conductor temperature.

Solution
In QuickField we specify the volume power density, which is Joule heating power per 1 meter of length [W/m] divided by the conductor cross-section area [m²].
The geometry model features symmetry, which allows reducing simulation domain.

Results
Temperature distribution in the soil and cables. Upper cable conductor temperature is 81°C. Bottom cable conductor temperature is 86°C.

• Download simulation files (files may be viewed using any QuickField Edition).