The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.

The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.

A well completion to convert a hydrocarbon production well into a geothermal well includes flow tubes to transport a working fluid through the well and a heat exchanger at a downhole location coupled to the flow tubes to exchange heat of the formation at the downhole location with the working fluid. A heat exchange fluid surrounds the heat exchanger at the downhole location to be heated by the formation at the downhole location. The heat exchanger heats the working fluid to a state in which the working fluid rises to the surface. At the surface, a power plant uses the heated working fluid to generate work. The working fluid is then cooled and returned to the downhole location to repeat the work generation cycle.

A well completion to convert a hydrocarbon production well into a geothermal well includes flow tubes to transport a working fluid through the well and a heat exchanger at a downhole location coupled to the flow tubes to exchange heat of the formation at the downhole location with the working fluid. A heat exchange fluid surrounds the heat exchanger at the downhole location to be heated by the formation at the downhole location. The heat exchanger heats the working fluid to a state in which the working fluid rises to the surface. At the surface, a power plant uses the heated working fluid to generate work. The working fluid is then cooled and returned to the downhole location to repeat the work generation cycle.

An open-loop type heat equalization device utilizes a heat exchange fluid as the carrier to transmit the thermal energy of a natural thermal energy storage body to an temperature differentiation body. The system includes an inclined or vertical heat gaining device that exchanges thermal energy with the natural thermal energy storage body, and first and second pipeline structures through which the fluid flows by convection or auxiliary pumping to the temperature differentiation body. The first pipeline system includes an outwardly-expanded arc-shaped fluid chamber and has a relatively larger volume than the second pipeline system to provide differential resistance to fluid flow at opposite ends of the heating gaining device.

An open-loop type heat equalization device utilizes a heat exchange fluid as the carrier to transmit the thermal energy of a natural thermal energy storage body to an temperature differentiation body. The system includes an inclined or vertical heat gaining device that exchanges thermal energy with the natural thermal energy storage body, and first and second pipeline structures through which the fluid flows by convection or auxiliary pumping to the temperature differentiation body. The first pipeline system includes an outwardly-expanded arc-shaped fluid chamber and has a relatively larger volume than the second pipeline system to provide differential resistance to fluid flow at opposite ends of the heating gaining device.

A geothermal system includes an outer vessel having a sidewall that is in contact with surrounding ground material. A geothermal pile is disposed within an interior volume of the outer vessel, wherein a first heat conducting liquid at least partially fills a space between an inner surface of the sidewall of the outer vessel and an outer surface of the geothermal pile when in an installed condition. A conduit disposed within an interior space of the geothermal pile conducts a second heat conducting liquid along a flow path within the geothermal pile toward a bottom end thereof and then back to an outlet at a top end thereof. During operation, heat is transferred from the surrounding ground to the second heat conducting liquid via the first heat conducting liquid within the space between the inner surface of the sidewall of the outer vessel and the outer surface of the geothermal pile.

A hardened solar thermal energy collector (STEC) system that is adapted to withstand a nuclear detonation or other powerful explosion in the vicinity. The STEC system comprises a plurality of collector tubes arranged side by side in an array that carry and circulate a working fluid, each of the plurality of collecting tubes having an upper radiation collection surface having a diffractive optical structure and a bottom surface, a supporting tray upon which each of the collector tubes is securely mounted, an insulated housing set beneath a ground surface level enclosing the plurality of collector rubes and supporting trays, and a secured underground geothermal storage unit fluidly coupled to the array of collector tubes. The housing, the plurality of collector tubes, and the tray are positioned such that topmost portions thereof are at the ground surface level or below.

A hardened solar thermal energy collector (STEC) system that is adapted to withstand a nuclear detonation or other powerful explosion in the vicinity. The STEC system comprises a plurality of collector tubes arranged side by side in an array that carry and circulate a working fluid, each of the plurality of collecting tubes having an upper radiation collection surface having a diffractive optical structure and a bottom surface, a supporting tray upon which each of the collector tubes is securely mounted, an insulated housing set beneath a ground surface level enclosing the plurality of collector rubes and supporting trays, and a secured underground geothermal storage unit fluidly coupled to the array of collector tubes. The housing, the plurality of collector tubes, and the tray are positioned such that topmost portions thereof are at the ground surface level or below.

A geothermal energy system utilizes supercritical CO2 turbine and a radial outflow reaction turbine, a Catherine Wheel having wheel arms, that spins around an axle to produce power. A fin portion extends from the radial portion at an offset angle, to an exhaust end. A first working fluid, such as supercritical carbon dioxide flows through an arm conduit within the wheel arm and a second working fluid, such as a hydrocarbon mixes with the first working fluid and both flow through a turbine. The turbine may be configured within the wheel arm conduit or mounted prior to the Catherine Wheel or any other radial outflow reaction turbine, or variable phase turbines available, and it turns as the combined working fluids expand and vaporize. The second working fluid may be condensed and recirculated while the first working fluid is expelled back into a geothermal reservoir.