Ormat Technologies, Inc.

Ormat Industries Ltd.

Ohad Zimron

Lucien Y Bronicki

Nadav Amir

Meir Rigal

Danny Batscha

Meir Regal

Shimon Hatzir

Lucien Yehuda Bronicki

A closed Rankine cycle power plant using an organic working fluid includes a solar trough collector for heating an organic working fluid, a flash vaporizer for vaporizing the heated organic working fluid, a turbine receiving and expanding the vaporized organic working fluid for producing power or electricity, a condenser for condensing the expanded organic working fluid and a pump for circulating the condensed organic working fluid to the solar trough collector. Heated organic working fluid in the flash vaporizer that is not vaporized is returned to the solar trough collector.

Power plant using organic working fluids

The present invention provides an improved, commercially available organic working fluid, which is operable under a broad range of temperatures, is thermally stable, has a high auto-ignition temperature, low freezing point and high critical temperature and is benign to the environment, and safe for human use. Such an organic working fluid is useful in organic Rankine cycle (ORC) power plants or units and other systems of the like as an intermediate fluid for heat-recovery wherein heat from various heat sources is transferred using the intermediate fluid to a further working fluid and converted into work, and the intermediate fluid is also exploited to produce electricity. Such organic working fluids are also operable as heat transfer fluids either in ORC power plants or units or in other heat transfer systems. For this purpose the present invention presents a working fluid comprising at least one highly branched, heavy iso-paraffin hydrocarbons, or a mixture of two or more of such hydrocarbons. Preferably, at least one highly branched iso-paraffin hydrocarbon is present as the major component (i.e. at least 50&#xb0;% by volume) in the working fluid. A preferred subclass of the class of the branched iso-paraffins which are suitable to be incorporated in organic working fluids of the present invention includes 8 to 20 carbon atom-containing hydrocarbons having at least one methyl radical (CH) arranged to achieve a highly stable compound.

Organic working fluids

A method for producing power from a heat source comprises the steps of: heating an intermediate fluid with heat from the heat source and producing a vaporized intermediate fluid in an intermediate fluid heater/vaporizer. Heat from the vaporized intermediate fluid vaporizes an organic liquid working fluid present in an organic working fluid vaporizer to form a vaporized organic working fluid and intermediate fluid condensate. The vaporized organic working fluid is expanded in an organic vapor turbine for generating power and producing expanded vaporized organic working fluid; the expanded organic vaporized working fluid being condensed to produce an organic fluid condensate with the organic fluid condensate being supplied to the organic fluid vaporizer. According to the present invention, prior to supplying the vaporized intermediate fluid to the organic fluid vaporizer the vaporized intermediate fluid is expanded in an intermediate fluid vapor turbine and power is produced.

Method of and apparatus for producing power from a heat source

A method and an apparatus for producing power from a heat source comprising a nonane heater/vaporizer, an intermediate fluid vapor turbine mounted on a shaft that receives and expands the vaporized nonane, an organic fluid vaporizer that receives the expanded vaporized nonane for supplying heat to liquid organic working fluid present in said organic fluid vaporizer and vaporizes said liquid organic working fluid with heat from the expanded vaporized nonane to form vaporized organic working fluid and a nonane condensate, a seal of said shaft being cooled using the nonane condensate by cooling and condensing hot pressurized vapor near the seal, and liquid containing such condensed hot pressurized vapor being supplied to a condensate drain vessel, the drained condensate being supplied to a line connected to a cycle pump of the nonane intermediate cycle, and an organic vapor turbine that expands the vaporized organic working fluid.

Method of and apparatus for cooling a seal for machinery

The present invention provides an improved, commercially available organic working fluid, which is operable under a broad range of temperatures, is thermally stable, has a high auto-ignition temperature, low freezing point and high critical temperature and is benign to the environment, and safe for human use. Such an organic working fluid is useful in organic Rankine cycle (ORC) power plants or units and other systems of the like; as an intermediate fluid for heat-recovery wherein heat from various heat sources is transferred using the intermediate fluid to a further working fluid and converted into work, and the intermediate fluid is also exploited to produce electricity. Such organic working fluids are also operable as heat transfer fluids either in ORC power plants or units or in other heat transfer systems. For this purpose the present invention presents a working fluid comprising at least one highly branched, heavy iso-paraffin hydrocarbons, or a mixture of two or more of such hydrocarbons. Preferably, at least one highly branched iso-paraffin hydrocarbon is present as the major component (i.e. at least 50% by volume) in the working fluid. A preferred sub-class of the class of the branched iso-paraffins which are suitable to be incorporated in organic working fluids of the present invention includes 8 to 20 carbon atom-containing hydrocarbons having at least one methyl radical (CH) arranged to achieve a highly stable compound.

A method is provided for cooling a seal located in a wall of a chamber and through which a movable shaft passes, the seal being heated by hot pressurized vapor that leaks through the seal into the chamber and internal friction. The method comprises the steps of: providing a chamber in which the seal is located and into which the hot pressurized vapor leaks; injecting cool liquid into the chamber in which the seal is located; and cooling and condensing the hot pressurized vapor in the chamber thus cooling the seal.

A seal heated by hot pressurized vapor is cooled by providing a chamber in which the seal is located and for containing vapor that leaks thereinto. The pressure in the chamber is reduced by connecting it to a source of low pressure; and liquid is supplied to the chamber at a pressure above the reduced pressure of the chamber and at a temperature below the temperature of vapor leaking into the chamber. The liquid is introduced into the chamber as droplets for contacting vapor that leaks thereinto thereby cooling the vapor and thus cooling the seal. The flow rate of the liquid is adjustable in accordance with the temperature of the liquid in the chamber.

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Gan Yavne, Israel

Ohad Zimron