| 摘要 |
A percussion mole for inserting a ground-loop for a geothermal heat-pump apparatus; the ground-loop includes a first pipe and a second pipe. The mole comprises: a percussive drive mechanism; a first passage connectable to the first pipe, for receiving a driving fluid via the first pipe and delivering it to the drive mechanism, during insertion of the ground-loop; a second passage connectable to the second pipe, for exhausting the driving fluid from the drive mechanism via the second pipe, during insertion of the ground-loop; and a connection connecting the first passage with the second passage. The connection includes a non-return valve arranged to restrict flow of the driving fluid from the first passage to the second passage during insertion of the ground loop but permit flow in the opposite direction,whereby after insertion, when the heat pump apparatus is in use, the ground-loop comprises the first and second pipes; the first and second passages; and the connection. |
