| 摘要 |
PURPOSE:To prevent freezing of the ground by interposing a partition pipe concentrically between a protection pipe inserted in an excavating hole and a hot water pipe, thereby to transmit heat of hot water in the hot water pipe to the peripheral ground efficiently. CONSTITUTION:A perforated protection pipe 3 is inserted in an excavating hole B of the peripheral ground A of a low-temperature underground structure, and granular material C such as fine stone or the like is charged between the pipe 3 and hole B. A partition pipe 5 and a hot water pipe 4 are inserted in the protection pipe 3. When hot water is circulated in the hot water pipe 4, underground water between the hot water pipe 4 and the partition pipe 5 is warmed so that the underground water decreases in density. On the other hand, the density of the underground water between the partition pipe 5 and the protection pipe 3 is not so lowered, so that there is a difference in density of the underground water between the inside and the outside of the partition pipe 5. The underground water between the protection pipe 3 and the partition pipe 5 flows in between the partition pipe 5 and the hot water pipe 4 to cause the convection there between, so that heat of hot water circulating in the hot water pipe 4 is efficiently transmitted to the peripheral ground A to prevent freezing of the ground A. |
