| 摘要 |
The underground steel container (1) which is heat insulated on parts of its surface contains unmanned telecommunications sets. It comprises a sealed entrance chute or manhole (5) with an airtight opening. The steel container is buried in the earth at a depth such that lower regions of the container lies in earth layers whose temperature remains essentially constant over the daynight period. The container is provided with heat insulation on its outer side, and the insulation is graded from the bottom of the container up to the top, including the airtight opening, in such a way that heat entering in the upper region of the container through the graded insulation is cycled through the wall of the lower region of the container to vent to atmosphere. Glass fibre fabric is used as an insulating material. |
