Heat pipe

The utility model relates to a heat transfer element belonging to the heat engineering field, in particular to a heat pipe, which can be connecting used and is a gravity heat pipe comprising a housing, an inner pipe and refrigerants or a heat pipe with a pipe core in the inner pipe and unrestricted heating segment position. The utility model is characterized in that: the bottom surface of the pipe heating segment has a cavate cavity having relative housing shape and size to the housing of the heat release segment; the inner pipe at heating segment of the heat pipe is a ring surface pipe and formed by two parallel surfaces surround the cavate cavity. When the heat transfer distance is long, the heat release segment of the prior heat pipe is inserted into the cavate cavity on the bottom surface of later heat pipe heating segment, which has relative shape and size to the housing of the heat release segment; the heat realized by the prior heat pipe is absorbed by the liquid refrigerant in the ring surface pipe formed by formed by two parallel surfaces surround the cavate cavity at the heat release segment of the later heat pipe and then sent to the heat release segment. Using the heat pipe, no heat is loss at the connection process and the problem of long-distance heat energy transmission is solved.