Method and apparatus for producing power from geothermal fluid

Abstract

Apparatus for utilizing geothermal fluid comprising a two-phase mixture of geothermal steam and brine produced by a production well, includes an input conduit connecting the production well with the separator which separates the geothermal fluid into high pressure geothermal steam and geothermal brine. A connecting conduit connects the separator to a geothermal power plant which produces power from the high pressure geothermal steam. The input conduit is shorter than said connecting conduit to reduce pressure losses due to two-phase flow in the input conduit. The geothermal power plant includes a topping steam turbine coupled to a generator, and a flow control mechanism for applying the high pressure geothermal steam to the topping steam turbine which is constructed and arranged to drive the generator and produce exhaust steam at a pressure greater than atmospheric pressure. A secondary separator receives the exhaust steam and produces condensate and dry low pressure steam which is applied to a condensing steam turbine coupled to a generator for producing power and exhaust steam that is below atmospheric pressure. The flow control system is effective to maintain a substantially constant flow rate of geothermal steam through he power plant in the face of decreasing pressure of the geothermal fluid.