Systems and methods relating to use of external air for inventory control of a closed thermodynamic cycle system or energy storage system, such as a reversible Brayton cycle system, are disclosed. A method may involve, in a closed cycle system operating in a power generation mode, circulating a working fluid may through a closed cycle fluid path. The closed cycle fluid path may include a high pressure leg and a low pressure leg. The method may further involve in response to a demand for increased power generation, compressing and dehumidifying environmental air. And the method may involve injecting the compressed and dehumidified environmental air into the low pressure leg.

In a cryogenic combined cycle power plant electric power drives a cryogenic refrigerator to store energy by cooling air to a liquid state for storage within tanks, followed by subsequent release of the stored energy by first pressurizing the liquid air, then regasifying the liquid air and raising the temperature of the regasified air at least in part with heat exhausted from a combustion turbine, and then expanding the heated regasified air through a hot gas expander to generate power. The expanded regasified air exhausted from the expander may be used to cool and make denser the inlet air to the combustion turbine. The combustion turbine exhaust gases may be used to drive an organic Rankine bottoming cycle. An alternative source of heat such as thermal storage, for example, may be used in place of or in addition to the combustion turbine.

In a cryogenic combined cycle power plant electric power drives a cryogenic refrigerator to store energy by cooling air to a liquid state for storage within tanks, followed by subsequent release of the stored energy by first pressurizing the liquid air, then regasifying the liquid air and raising the temperature of the regasified air at least in part with heat exhausted from a combustion turbine, and then expanding the heated regasified air through a hot gas expander to generate power. The expanded regasified air exhausted from the expander may be used to cool and make denser the inlet air to the combustion turbine. The combustion turbine exhaust gases may be used to drive an organic Rankine bottoming cycle. An alternative source of heat such as thermal storage, for example, may be used in place of or in addition to the combustion turbine.

A heat engine is disclosed. The heat engine comprises a housing, a first liquid and a second liquid located within the housing. The first liquid has a higher density and lower boiling point than the second liquid. The heat engine further comprises a heat exchanger which transfers heat to the first liquid to evaporate the first liquid to form a first liquid vapour. The heat engine also comprises at least one fluid flow member which to moves in response to a fluid flow created by the interaction of the first liquid vapour and the second liquid. The liquid-gas phase change of the first fluid provides an alternative mechanism for converting heat into work with numerous advantages. The heat engine has minimal moving parts, a relatively long lifetime, does not require a specific fuel, does not directly release toxic or un-environmentally friendly gases, and can be adapted to a specific source of waste heat.

A process for energy management includes actuating a closed cyclic thermodynamic transformation, first in one direction in a charge configuration/phase and then in the opposite direction in a discharge configuration/phase, between a casing for the storage of a working fluid other than atmospheric air, in gaseous phase and in equilibrium of pressure with the atmosphere, and a tank for the storage of the working fluid in liquid or super-critical phase with a temperature close to its own critical temperature. In the charge phase, the process accumulates heat and pressure. In the discharge phase, the process generates energy. The process includes actuating, with at least one part of the working fluid, at least one closed thermodynamic cycle, even at the same time as the charge phase or as the discharge phase; and heating the working fluid by means of at least one oxy-combustion within the closed thermodynamic cycle.

A process for energy management includes actuating a closed cyclic thermodynamic transformation, first in one direction in a charge configuration/phase and then in the opposite direction in a discharge configuration/phase, between a casing for the storage of a working fluid other than atmospheric air, in gaseous phase and in equilibrium of pressure with the atmosphere, and a tank for the storage of the working fluid in liquid or super-critical phase with a temperature close to its own critical temperature. In the charge phase, the process accumulates heat and pressure. In the discharge phase, the process generates energy. The process includes actuating, with at least one part of the working fluid, at least one closed thermodynamic cycle, even at the same time as the charge phase or as the discharge phase; and heating the working fluid by means of at least one oxy-combustion within the closed thermodynamic cycle.

A binary power plant system, comprising: a vaporizer for vaporizing an organic motive fluid circulating in a closed Organic Rankine Cycle (ORC) by a heat source fluid in heat exchange relation therewith and producing wet organic motive fluid vapor having a quality of at least approximately 80 percent; and a single organic vapor, turbine of said ORC: having an inlet for receiving the wet organic motive fluid vapor, wherein organic motive fluid vapor is expanded in said single organic vapor turbine without causing turbine blades of the turbine to be subjected to erosion.

A binary power plant system, comprising: a vaporizer for vaporizing an organic motive fluid circulating in a closed Organic Rankine Cycle (ORC) by a heat source fluid in heat exchange relation therewith and producing wet organic motive fluid vapor having a quality of at least approximately 80 percent; and a single organic vapor, turbine of said ORC: having an inlet for receiving the wet organic motive fluid vapor, wherein organic motive fluid vapor is expanded in said single organic vapor turbine without causing turbine blades of the turbine to be subjected to erosion.

A heat engine including a compressor, an expander, a reactor in which first and second reactants in a working fluid can react with each other, the reactor arranged between the compressor and the expander, and a condenser for condensing a gas in the working fluid, the condenser arranged between the expander and the compressor. There is also provided a method of operating a heat engine.

A heat engine including a compressor, an expander, a reactor in which first and second reactants in a working fluid can react with each other, the reactor arranged between the compressor and the expander, and a condenser for condensing a gas in the working fluid, the condenser arranged between the expander and the compressor. There is also provided a method of operating a heat engine.