Interference-free underground heat exchanger for changing waste well into geothermal well

The utility model belongs to the technical field of development and utilization of waste well geothermal energy, and relates to an underground heat exchanger, in particular to a non-interference underground heat exchanger used for changing a waste well into a geothermal well. The utility model discloses a non-interference underground heat exchanger for changing a waste well into a geothermal well. The non-interference underground heat exchanger comprises an outer sleeve and a central pipe arranged in the outer sleeve, the heat exchanger further comprises a porous heat exchange tube, the porous heat exchange tube comprises an inner ring wall and an outer ring wall, a middle hole channel with the inner diameter consistent with the inner diameter of the central tube is formed in the inner ring of the porous heat exchange tube, and a capillary hole channel is formed between the inner ring wall and the outer ring wall. The upper end of the porous heat exchange tube is respectively connected with the outer sleeve a