A ladder-structural gravity-assisted-heat-pipe geothermal energy recovery system without liquid-accumulation effect, comprises a ladder-structural gravity-assisted heat pipe, a condenser, and a liquid tank. The ladder-structural gravity-assisted heat pipe comprises a return pipe, an outer pipe and an inner pipe. The return pipe is provided in a space between the outer pipe and the inner pipe and communicated with the liquid tank, and the space between the outer pipe and the inner pipe is divided to form a ladder structure. A liquid working medium flows from the liquid tank through the return pipe into each section sequentially, absorbs heat from a high-temperature rock through a wall of the outer pipe, vaporizes into a gaseous working medium, gets into the inner pipe, and rises to the condenser to condense and flows to the liquid tank to circulate. Such design greatly improves the heat transfer efficiency in geothermal energy recovery using ultra-long heat pipes.

A borehole is bored to a borehole target depth in a site and a geothermal heat exchanger is inserted into and then secured in the borehole at the desired depth. Once the heat exchanger has been secured in the borehole, the heat exchanger has a closed distal end and an open proximal end and has at least one fluid path between the closed distal end and the open proximal end, with installation fluid disposed in the fluid path(s). After securing the heat exchanger in the borehole and before excavation of a portion of the site immediately surrounding the borehole, the heat exchanger is temporarily sealed by installing, through the open proximal end, at least one respective internal seal in each fluid path. For each fluid path, the internal seal(s) will be disposed below a respective notional subgrade depth and excavation of the site immediately surrounding the borehole can proceed.

An intelligent heat pump system having a dual heat exchanger structure includes a heat source side heat exchange member, a heat pump, an external expansion valve, a refrigerant-water heat exchanger, a heat storage tank, and a target side end unit. A refrigerant flows through the heat pump, the refrigerant-water heat exchanger, and the target side end unit, and in a non-air-conditioning state for the target site, circulates between the heat pump and the refrigerant-water heat exchanger, so that cooled or heated water is stored in the heat storage tank. In an air-conditioning state for the target site, the heat pump and the heat storage tank supply cooling and heating to the target site, so that the power consumption for normal operation is reduced in order to improve the operation efficiency of the intelligent heat pump system.

An intelligent heat pump system having a dual heat exchanger structure includes a heat source side heat exchange member, a heat pump, an external expansion valve, a refrigerant-water heat exchanger, a heat storage tank, and a target side end unit. A refrigerant flows through the heat pump, the refrigerant-water heat exchanger, and the target side end unit, and in a non-air-conditioning state for the target site, circulates between the heat pump and the refrigerant-water heat exchanger, so that cooled or heated water is stored in the heat storage tank. In an air-conditioning state for the target site, the heat pump and the heat storage tank supply cooling and heating to the target site, so that the power consumption for normal operation is reduced in order to improve the operation efficiency of the intelligent heat pump system.

A refrigeration and/or heat transfer device includes a heating section and cooling section, a release member, and a one-way check valve affixed together in a continuous loop so working fluid may flow in one direction therein. The heating section absorbs heat and transfers such heat to the working fluid, thereby heating, expanding and increasing pressure upon the working fluid therein. The pressurized working fluid is released in a regulated manner from the heating section to the cooling section, thereby carrying the heat away. The released working fluid cools and transfers its heat to the surroundings within the cooling section. As released working fluid enters the cooling section, such fluid displaces already cooled working fluid, pushing such fluid through the one-way check valve back into the heating section to absorb heat. The working fluid may undergo a phase change or remain in a single phase throughout to enhance heat transfer.

Operational protocol sequences for recovering energy from a thermally productive formation are disclosed. Sealing, drilling, multiranging, power production and distribution techniques in predetermined sequences for well formation are utilized to recover energy regardless of thermal gradient variation, formation depth and permeability and other anomalies or impedances

A geothermal pile for harvesting electricity from a gradient of temperature between ambient air and an underground area is provided. The geothermal pile includes an elongated thermally-conductive body, a thermoelectric cell and an electrical output. The elongated thermally-conductive body has a first end and a second end opposite the first end. The second end is configured to be introduced, in use, into an underground area. The thermoelectric cell is provided at the first end so as to be exposed to ambient air when the second end is introduced into the underground area. The thermoelectric cell is in thermal contact with the second end of the elongated thermally-conductive body and is configured to generate electricity from a gradient of temperature between a first temperature of the ambient air and a second temperature of the underground area. The electrical output is electrically connected to the thermoelectric cell.

A geothermal pile for harvesting electricity from a gradient of temperature between ambient air and an underground area is provided. The geothermal pile includes an elongated thermally-conductive body, a thermoelectric cell and an electrical output. The elongated thermally-conductive body has a first end and a second end opposite the first end. The second end is configured to be introduced, in use, into an underground area. The thermoelectric cell is provided at the first end so as to be exposed to ambient air when the second end is introduced into the underground area. The thermoelectric cell is in thermal contact with the second end of the elongated thermally-conductive body and is configured to generate electricity from a gradient of temperature between a first temperature of the ambient air and a second temperature of the underground area. The electrical output is electrically connected to the thermoelectric cell.

Systems and methods for geothermal power generation using a closed-loop of liquid having low boiling temperature. A system for generating electricity includes: a storage tank to store a specific liquid, which has a boiling point of under 90 degrees Celsius; a closed-loop pipe sub-system, which penetrates underground to a depth of between 1,000 to 2,500 meters, and transports therein the specific liquid downwardly underground and then upwardly back towards ground level, and causes at least a portion of the specific liquid to boil underground due to proximity to a natural geothermal heat source; at least one turbine associated with an electric power generator, connected above ground level to the closed-loop pipe sub-system, to receive steam that results in from underground boiling of the specific liquid, to pass the steam through the turbine, and to generate electric power through the electric power generator

An intelligent heat pump system having a dual heat exchanger structure includes a heat source side heat exchange member, a heat pump, an external expansion valve, a refrigerant-water heat exchanger, a heat storage tank, and a target side end unit. A refrigerant flows through the heat pump, the refrigerant-water heat exchanger, and the target side end unit, and in a non-air-conditioning state for the target site, circulates between the heat pump and the refrigerant-water heat exchanger, so that cooled or heated water is stored in the heat storage tank. In an air-conditioning state for the target site, the heat pump and the heat storage tank supply cooling and heating to the target site, so that the power consumption for normal operation is reduced in order to improve the operation efficiency of the intelligent heat pump system.