Method and apparatus for producing power from geothermal fluid

Abstract

A method for producing power from geothermal fluid includes: separating the geothermal fluid in a flash tank into geothermal vapor comprising steam and non-condensable gases, and geothermal brine; supplying the geothermal vapor to a vaporizer; vaporizing a preheated motive fluid in the vaporizer using heat from the geothermal vapor to produce heat-depleted geothermal vapor and vaporized motive fluid, wherein the heat content in the geothermal vapor exiting the flash tank is only enough to vaporize the preheated motive fluid in the vaporizer; expanding the vaporized motive fluid in a vapor turbine producing power and expanded vaporized motive fluid; condensing the expanded vaporized motive fluid in a condenser to produce condensed motive fluid; and preheating the condensed motive fluid in a preheater using heat from the heat-depleted geothermal vapor and the geothermal brine, thereby producing the preheated motive fluid, make-up water and heat-depleted geothermal brine.