| 摘要 |
The pipe structure is inserted in a vertical hole (1) in the ground, and has a heat carrier fluid circulating through the inner pipe (5) and the space between the outer pipe (4) and the wall of the hole. The inner pipe has a thinner wall than the outer, and end parts which have a collar formation tightly joined to the end parts of the outer pipe (4). At least one of the collar structures (8) is softly arched to absorb the dimension alterations of the pipes determined by temp. variations. |
