Abstract: A geothermal development system includes a ground lifting system, a large-diameter shaft, an underground high temperature and high pressure heat transfer pool, a heat transfer diversion channel, a hot mine blasting fracture reservoir formed by an inlet blasting tunnel and a main tunnel, and a removable sealing device. The injection pipe and the collection pipe are set along the large diameter silo wall in the geothermal development system. The injection pipe is connected to the collection pipe through the heat transfer diversion channel in the dry hot rock. The circulation main roadway is arranged around the underground high temperature and high pressure heat transfer pool. Multiple blasting roadways are set along the main roadway level to form hot mine blasting fracture reservoir with loose blasting by caving method. A movable sealing device is arranged above the blasting layer of the large-diameter shaft.

Abstract: Within the technical field of detecting a mining-induced failure range of rock mass, and particularly relating to a graded-pressure drop type detection system and detection method of borehole cracks, a detection system is provided including a test probe, a drilling rig, a drill pipe and a control operation platform. The test probe includes a plugging device and a pressure conversion assembly. The pressure conversion assembly is connected with the plugging device at the rear end through a connected pipe and includes a first stage pressure converting device and a second stage pressure converting device. The detection system simplifies the existing operating system, avoids the problem of drill pipes winding in drill hole, realizes plugging process and detection process with the same external water source, and ensures that the plugging process and the observation process operate under respective predetermined pressures.

Abstract: A graded pressure drop type multi stage water injection device and method based on fracture observation. The device includes a test probe, a propulsion system and a control system. The test probe includes a plugging device, a pressure conversion assembly and a connected pipe. The rubber bag is wrapped around the outer end of the water leakage pipe, is fixed to both ends of the joints through a fastening iron ring and forms a blocked cavity with the water leakage pipe. The device integrates the plugging and detection system, and uses the same external water source to operate the plugging process and detection process under their respective pressures, thereby making pressure conversion more stable, solving the problem of winding the drill pipe and the hose in the propulsion process, realizing multi stage measurement in each propulsion and improving measurement efficiency.