Method and apparatus for converting heat from geothermal fluid to electric power

A method for implementing a thermodynamic cycle comprising the steps of:

• expanding a superheated gaseous working stream, transforming its energy into usable form and producing a spent stream;
• reheating and expanding the spent stream, to transform its energy into usable form;
• heating a multicomponent oncoming liquid working stream, by partially condensing the spent stream, to produce a heated liquid working stream;
• completely condensing the spent stream, after heat produced by partially condensing the spent stream has been used to heat the multicomponent oncoming liquid working stream, to produce the multicomponent oncoming liquid working stream;
• evaporating the heated liquid working stream using heat produced by a geothermal external heat source to form a gaseous working stream;
• and
• superheating the gaseous working stream to form the superheated gaseous working stream.

A method for implementing a thermodynamic cycle comprising the steps of:

• expanding a superheated gaseous working stream, transforming its energy into usable form and producing a spent stream;
• reheating the spent stream with heat transferred from a geothermal external heat source;
• expanding the spent stream to transform its energy into usable form;
• further evaporating a second part of a partially evaporated multicomponent oncoming liquid working stream, by partially condensing the spent stream, to produce a second part of a further evaporated working stream;
• partially evaporating a second enriched substream with heat transferred from the further condensation of the spent stream to form a second part of a partially evaporated enriched substream;
• preheating an enriched substream and a lean substream with heat transferred from the further condensation of the spent stream to form a preheated enriched substream and a preheated lean substream;
• partially evaporating a first liquid substream with heat transferred from the further condensation of the spent stream to form a partially evaporated liquid substream;
• condensing completely the spent stream to form a first liquid working stream;
• pumping the first liquid working stream to an increased pressure;
• separating the first liquid working stream into the first liquid substream and a second liquid substream;
• separating the partially evaporated liquid substream into a vapor stream and a liquid stream, after the first liquid substream has been partially evaporated with heat transferred from the further condensation of the spent stream to form the partially evaporated liquid substream, the liquid stream comprising the lean substream, the lean substream including a lower percentage of a low boiling component than is contained in the first liquid working stream;
• combining the vapor stream with the second liquid substream to form the enriched substream, the enriched substream enriched with a higher percentage of a lower boiling component than is contained in the first liquid working stream;
• completely condensing the enriched substream and pumping the enriched substream to an increased pressure prior to preheating the enriched substream with heat transferred from the further condensation of the spent stream to form the preheated enriched substream;
• pumping the lean substream to an increased pressure prior to preheating the lean substream with heat transferred from the further condensation of the spent stream to form the preheated lean stream;
• separating the preheated enriched substream into a first enriched substream and the second enriched substream prior to the second enriched substream being partially evaporated with heat transferred from the further condensation of the spent stream to form the second part of the partially evaporated enriched substream;
• partially evaporating the first enriched substream with heat transferred from the geothermal external heat source to form a first part of the partially evaporated enriched substream;
• heating the preheated lean substream with heat transferred from the geothermal external heat source to form a heated lean substream;
• combining the first and second parts of the partially evaporated enriched substream to form the partially evaporated enriched substream;
• combining the heated lean substream with the partially evaporated enriched substream to form the partially evaporated multicomponent oncoming liquid working stream;
• separating the partially evaporated multicomponent oncoming liquid working stream into the second part of the partially evaporated multicomponent oncoming liquid working stream and a first part of the partially evaporated multicomponent oncoming liquid working stream prior to further evaporating the second part of the partially evaporated multicomponent oncoming liquid working stream, by partially condensing the spent stream, to produce the second part of the further evaporated working stream;
• further evaporating the first part of the partially evaporated multicomponent oncoming liquid working stream with heat transferred from the geothermal external heat source to form a first part of the further evaporated working stream;
• combining the first and second parts of the further evaporated working stream to form the further evaporated working stream;
• completely evaporating the further evaporated working stream with heat produced by the geothermal external heat source to form a gaseous working stream;
• and
• superheating the gaseous working stream with heat produced by the geothermal external heat source to form the superheated gaseous working stream.

A method for implementing a thermodynamic cycle comprising the steps of:

• expanding a gaseous working stream, transforming its energy into usable form and producing a spent stream;
• partially condensing the spent stream to provide heat;
• forming an oncoming liquid working stream that begins to evaporate at a temperature that is lower than the temperature at which the spent stream begins to condense;
• and
• evaporating the oncoming liquid working stream using heat produced by partially condensing the spent stream, and heat from an external heat source, to form the gaseous working stream.

Apparatus for implementing a thermodynamic cycle comprising:

• means for expanding a gaseous working stream, transforming its energy into usable form and producing a spent stream;
• a heat exchanger for partially condensing the spent stream and for transferring heat from the spent stream as it begins to condense to partially evaporate an oncoming liquid working stream;
• means for forming the oncoming liquid working stream that begins to evaporate at a temperature that is lower than the temperature at which the spent stream begins to condense;
• and
• an external heat source for completely evaporating the oncoming liquid working stream, using heat produced by the external heat source, to form the gaseous working stream.