A geothermal energy transfer and utilization system abstracts thermal energy stored in hot solute-bearing well water to generate super-heated steam from an injected flow of clean water; the super-heated steam is then used for operating a turbine-driven pump at the well bottom for pumping the hot solute-bearing water at high pressure and always in liquid state to the earth's surface, where it is used by transfer of its heat to a closed-loop vapor generator-turbine-alternator combination for the generation of electrical or other power. Cooled, clean water is regenerated by the surface-located system for re-injection into the deep well and the residual concentrated solute-bearing water is pumped back into the earth. The invention features filter apparatus installed within the well at the location of the vapor generator-turbine-pump apparatus for removal of solid matter from the re-injected water before its use for lubrication of turbine and pump bearings and before conversion into a working fluid for driving the deep well turbine.
A geothermal energy recovery system of improved life duration makes use of thermal energy stored in hot, solute-bearing well water as it is pumped upward to the earth's surface through an extended heat exchange element for continuously heating a downward flowing organic working fluid to a supercritical state. Some of the energy of the latter fluid is used within the well for operating a turbine-driven pump for pumping the hot well water at high pressure and always in liquid state to the earth's surface, where it is reinjected into the earth in a second well. After driving the deep-well turbine-driven pump, the organic fluid still in supercritical state arises toward the earth's surface in a thermally insulated conduit; at the earth's surface, vapor turbine electrical power generation equipment is driven by the ascending organic fluid, after which it is returned into the well for re-heating in the extended heat exchanger. The invention provides a long life, closed-loop fluid lubricant pumping and cooling system for the bearings of the turbine and brine pump system, normally isolated from the working fluid loop and the hot brine pumping and heat exchange loop. Should the pressure level within the lubricant loop fall below a predetermined level, auxiliary means are provided for coupling working fluid into the lubrication loop to maintain the pressure within the loop above that of the hot brine, thus excluding intrusion of the corrosive brine.
