Abstract: The present invention provides a method for producing load-following power using low to medium temperature heat source fluid comprising the steps of: reducing the power level produced by a Rankine cycle power plant producing load-following power operating on a low to medium temperature heat source fluid during one period of time; storing heat not used during the first period of time; and using the heat stored for producing power during a second period of time.

Abstract: The present invention provides a method for producing load-following power using low to medium temperature heat source fluid comprising the steps of reducing the power level produced by a Rankine cycle power plant producing load-following power operating on a low to medium temperature heat source fluid during one period of time; storing heat not used during the first period of time; and using the heat stored for producing power during a second period of time.

Abstract: According to present invention, a method is provided for operating a multi-heat source power plant using a low-medium temperature heat source fluid, wherein the multi-heat source power plant includes a turbine or expander run by an organic motive fluid, comprising preheating the organic motive fluid using the low-medium temperature heat source fluid and thereafter providing further heat from an additional heat source to vaporize the motive fluid which is supplied to the turbine or expander. Furthermore, in an embodiment of the present invention, the present invention provides an apparatus comprising a heat exchanger suitable to pre-heat an organic motive fluid with a low-medium temperature geothermal fluid, and solar energy collecting means suitable to directly or indirectly provide heat to the pre-heated organic motive fluid for heating and vaporizing the motive fluid.

Abstract: The present invention provides a power plant system for producing power using a source of steam, comprising a vaporizer into which steam from a source of steam is supplied, for vaporizing organic working fluid flowing through the vaporizer; at least one turbine wherein one of the turbines is an organic vapor turbine to which the vaporized working fluid is supplied and which is suitable for generating electricity and producing; expanded organic vapor; a recuperator for heating organic vapor condensate flowing towards the vaporizer the expanded organic vapor exhausted from the organic vapor turbine and two or more stages of preheating means for additionally heating organic working fluid exiting the recuperator and flowing towards the vaporizer, wherein fluid extracted from one of the turbine is delivered to one of the stages of preheating means.

Abstract: According to present invention, a method is provided for operating a multi-heat source power plant using a low-medium temperature heat source fluid, wherein the multi-heat source power plant includes a turbine or expander run by an organic motive fluid, comprising preheating the organic motive fluid using the low-medium temperature heat source fluid and thereafter providing further heat from an additional heat source to vaporize the motive fluid which is supplied to the turbine or expander. Furthermore, in an embodiment of the present invention, the present invention provides an apparatus comprising a heat exchanger suitable to pre-heat an organic motive fluid with a low-medium temperature geothermal fluid, and solar energy collecting means suitable to directly or indirectly provide heat to the pre-heated organic motive fluid for heating and vaporizing the motive fluid.

Abstract: The present invention provides a power plant system for producing power using a source of steam, comprising a vaporizer into which steam from a source of steam is supplied, for vaporizing organic working fluid flowing through the vaporizer; at least one turbine wherein one of the turbines is an organic vapor turbine to which the vaporized working fluid is supplied and which is suitable for generating electricity and producing; expanded organic vapor; a recuperator for heating organic vapor condensate flowing towards the vaporizer the expanded organic vapor exhausted from the organic vapor turbine and two or more stages of preheating means for additionally heating organic working fluid exiting the recuperator and flowing towards the vaporizer, wherein fluid extracted from one of the turbine is delivered to one of the stages of preheating means.

Abstract: A plurality of independent, closed Rankine cycle power plants, each of which has a vaporizer, is operated by serially applying a medium or low temperature source fluid to the vaporizers of the power plants for producing heat depleted source fluid. A preheater is provided for each vaporizer; and said heat depleted source fluid is applied to all of the preheaters in parallel. The heat depleted source fluid thus serves to heat the operating fluid to the evaporization temperature, while the source fluid applied to the vaporizers supplies the latent heat of vaporization to the operating fluid of the power plant. The present invention is advantageous, as compared to a conventional cascaded power plant of the type described, because the temperature drop of the source fluid can be increased without reducing the efficiency. Alternatively, the temperature drop can be maintained but the efficiency can be increased. In either case, the power produced by the power plant according to the present invention is increased.

Abstract: A plurality of independent, closed Rankine cycle power plants, each of which has a vaporizer, is operated by serially applying a medium or low temperature source fluid to the vaporizers of the power plants for producing heat depleted source fluid. A preheater is provided for each vaporizer; and said heat depleted source fluid is applied to all of the preheaters in parallel. The heat depleted source fluid thus serves to heat the operating fluid to the evaporization temperature, while the source fluid applied to the vaporizers supplies the latent heat of vaporization to the operating fluid of the power plant. The present invention is advantageous, as compared to a conventional cascaded power plant of the type described, because the temperature drop of the source fluid can be increased without reducing the efficiency. Alternatively, the temperature drop can be maintained but the efficiency can be increased. In either case, the power produced by the power plant according to the present invention is increased.