Patent ID: 7356993

Claim:
A method of extracting heat from a hot gas to generate electricity using a multi-component working fluid comprising ammonia and water in a single continuous stream, comprising the steps of: a. pressuring said working fluid in liquid form in a feedpump; b. heating said working fluid liquid in a recuperator to its boiling point and partially vaporizing it; c. further heating the entirety of said working fluid liquid-vapor mixture in a heater to fully vaporize it and further heating the entirety of said working fluid to a superheated vapor state, said heater comprising a heat exchanger using said hot gas that supplies heat to said working fluid liquid-vapor mixture and arranged in counter-flow to said working fluid mixture; d. reducing the pressure and enthalpy of said superheated working fluid mixture by expansion through a turbine, and using said turbine to generate electricity; e. cooling and partially condensing the low-pressure working fluid mixture emerging from said turbine in said recuperator, which is arranged in counter-flow to said high-pressure working fluid liquid from said feedpump, and partially vaporizing said high-pressure working fluid liquid; f. further cooling and completely condensing said low-pressure working fluid in a cooler, said cooler being a heat exchanger using a second fluid that absorbs heat from the working fluid and arranged in counter-flow to the working fluid; g. returning the low-pressure liquid working fluid leaving said cooler to said feedpump to form a closed loop system.