Coaxial sleeve heat exchanger used in medium-depth stratum drill hole

Abstract

The invention relates to a coaxial sleeve heat exchanger used in a medium-depth stratum drill hole. The coaxial sleeve heat exchanger comprises an outer pipe and a heat insulation inner pipe coaxially arranged in the outer pipe, an arc-shaped protrusion is arranged at the bottom end of the inner side of the outer pipe, threaded blades are arranged on the inner wall of the outer pipe, and the heat exchange area is increased; and the bottom end of the inner pipe is suspended in the outer pipe, circulating water flows in from a water inlet of a sleeve head at the upper portion of the outer pipe, flows into an opening formed in the radial direction of the bottom end of the inner pipe after exchanging heat with the stratum through an annular space, and then flows out from a water outlet in the top end of the inner pipe through an inner channel of the inner pipe. According to the coaxial sleeve heat exchanger used in the medium-deep stratum drill hole, on the premise that underground hot water is not extracted, only medium-deep layer geothermal energy is exchanged, and sustainable development and utilization of medium-deep layer geothermal resources are achieved; and the spiral blades are arranged on the inner side wall of the outer sleeve, the heat exchange area is increased, the heat taking capacity of a single well is increased, and the heat supply capacity of a ground heat supply system is improved.

Description

technical field [0001] The invention belongs to the technical field of geothermal energy application, and in particular relates to a coaxial casing heat exchanger used in boreholes in medium-deep formations. Background technique [0002] In today's society, energy has become the key to national development. Extensive use of fossil energy will lead to serious environmental problems, which has become a severe challenge for the whole world. Geothermal energy is clean, environmentally friendly, stable, and recyclable, making it a realistic and competitive renewable energy source. At present, the medium-to-deep geothermal central heating technology is relatively mature, and the use of clean energy to replace fossil energy has become the general trend. [0003] As the main part of geothermal extraction technology, the current research on coaxial casing heat exchangers is facing many problems that need to be solved urgently, such as low return water temperature and low comprehensi...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a coaxial casing heat exchanger used in medium-deep formation boreholes to solve the problem of low return water temperature and low comprehensive utilization efficiency of geothermal resources in existing coaxial casing heat exchangers The problem

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