Geothermal power plant with high efficiency

Abstract

Abstract In a preferred embodiment, there is provided a closed-system geothermal power plant operative and maintained at super-critical pressure in the utilization of carbon dioxide as the power fluid used in the cycle for the driving of a super-critical pressuretype gas turbine(s) and associated generator(s) to electricity, from which exhaust effluent still in a gaseous state but at reduced pressure nevertheless still at super-critical pressure and temperature is passed through a heat-exchanger(s) and thereafter passed to a super-critical-type condenser(s) in which the gaseous carbon dioxide effluent is condensed to a liquid state by a fluid with a lower temperature and from which condenser(s) the liquid carbon dioxide still at super-critical pressure is fed to a pump(s) which increases the pressure on the liquid carbon dioxide effluent from the condenser(s) and is directed to heat recuperator(s) and to the heat exchanger(s) in segregated heat-exchanger relationship with the turbine(s) effluent gas, resulting in further elevating the temperature of the high-pressure super-critical fluid carbon dioxide, and from the heat-exchanger carbon dioxide is passed downwardly through down-flow conduit(s) extending downwardly through a well space heat exchanger including a heavy insulating liquid, the downwardly extending conduit(s) extending into a subterranean cavity within preferably basalt rock within which cavity the gas carbon dioxide at the super-critical temperature and pressure in a gas state absorbs sufficient heat energy to increased carbon dioxide parameters to higher super-critical parameters of carbon dioxide having both elevated super-critical temperature and elevated super-critical pressure, which thereafter is channeled upwardly through up-flow conduits of a type to withstand elevated super-critical temperatures and pressures, the up-flow conduit(s) passing upwardly through the well space and again to the turbine inlet. The basalt cavity includes upper and lower chambers spaced apart from one-another by two preheater chambers which communication with the upper chamber(s) with a pressurized water heat-exchanger medium flowing cyclically between the upper, preheater and lower chambers, upwardly through an upper well of the lower chamber(s) extending from an upper part of the lower chamber(s) to an upper portion of the upper chamber(s), and flowing from a lower portion of the upper chamber(s) through the preheater chambers downwardly through well(s) to the lower chamber(s), there being preferably a plurality of such down-flow wells from the preheater chamber(s) to the lower chamber(s). These wells are preferably in close juxtaposition and contact with the lower chamber(s) side walls for heat exchange flow of geothermal heat into the channeled water, the pressurized water being flowed through the upper chamber in a state of isolated heat-exchanger relationship with the fluid carbon dioxide flowing through the upper chamber(s), the carbon dioxide in the upper chamber(s) preferably flowing through a plurality of parallelflow serpentine conduits to the upper chamber(s) carbon dioxide gas outlet, preferably the well being isolated from the upper chamber(s) by a pressure-resistent barrier wall with appropriate conventional pressure-relief emergency valves. Further enhancing the present invention is a novel condensation and sub-cooling system, equipped with the condenser, two heat recuperators, an electric motor, a turbo-compressor, a turbine and conduits, which permits recovery of heat eliminated from the power cycle fluid during its process of condensation and subcooling and insures the compression of fluid after this to high super-critical pressure. After the system accomplished condensation and sub-cooling of the power cycle fluid, it returns totally the absorbed heat to the power cycle fluid without any losses of significance. By the harnessing of energy there is prevention of atmospheric thermal pollution.

Inventors

• 👤 Petru Baciu

Bibliographic Details