A kind of immersed tube device for middle-deep geothermal well

Abstract

The invention discloses an immersed pipe device of a medium-deep geothermal well. The device is placed at the bottom in an outer sleeve of the geothermal well, and comprises an upper section, a middlesection and a lower section; the upper section consists of inner sleeves; the middle section consists of a metal expansion joint, a nonmetal expansion joint and a fixed immersed pipe; and the lower section consists of a movable immersed pipe and a guide head connected in sequence. The movable immersed pipe and the fixed immersed pipe are connected through pipe inner and outer bosses; the bottom of the movable immersed pipe is connected with the guide head; the fixed immersed pipe is of a hollow structure, and a sandwich layer is filled with tungsten diselenide; the surface of the movable immersed pipe is coated with a tungsten diselenide film coating layer; multiple layers of jet holes with gradually increased apertures are formed in the peripheral direction from top to bottom; and a spiral rib is mounted on the inner side of the guide head. Through the mode of coating low-heat-conducting-coefficient materials on the sandwich layer and the coating layer, the heat transfer short-circuit degree of metal immersed pipes is reduced; and through the movable connecting mode of the fixed and movable immersed pipes, the bottom dead area range is shortened, and the contribution of a heat exchange well is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of geothermal energy exploitation and utilization, and in particular relates to an immersed tube device for mid-deep geothermal wells. [0002] technical background [0003] At present, the utilization technology of shallow geothermal energy in my country is basically mature, the utilization of medium and deep geothermal energy is still in the demonstration application stage, and the utilization technology of deep geothermal energy is still in the research and development stage. [0004] The utilization of mid- to deep-layer geothermal energy usually adopts the mode of "extracting heat without water", that is, using fluid heat transfer medium to exchange heat through geothermal wells to absorb heat from underground rocks, and then flow through ground heat exchangers to release heat. Downhole heat exchange is generally Cased geothermal wells are used. Since the depth of medium-deep geothermal wells is usually...

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Problems solved by technology

[0006] Purpose of the invention: The present invention provides a medium-deep geothermal well for problems such as expansion and contraction of the inner casing during construction and opening and closing, high thermal conductivity of the inner casing in the metal section, and difficulty in arranging return holes in the guide head. Immersed tube device for geothermal well

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