This invention relates generally to hydro-turbine drive methods and systems and, more particularly, to hydro-turbine drive methods and systems such as for application for various rotary machineries including producing a high pressure fluid with at least one fluid pump by utilizing a fluid heater to create a fluid and vapor mixture for producing mechanical shaft power.

Systems and processes provide for a thermal process to transform sludge (and a variety of other natural waste materials) into electricity. Dewatered sludge and other materials containing a high amount of latent energy are dried into a powdered biofuel using a drying gas produced in the system. The drying gas is recirculated and is heated by the biofuel produced in the system, waste heat (from turbines or internal combustion engines), gas (including natural gas or digester gas) and/or oil. The biofuel is combusted in a boiler system that utilizes a burner operable to burn biofuel and produce heat utilized in a series of heat exchangers that heat the recirculating drying air and steam that powers the turbines for electricity production.

An energy storage plant includes a casing for the storage of a working fluid other than atmospheric air, in a gaseous phase and in equilibrium of pressure with the atmosphere; a tank for the storage of said working fluid in a liquid or supercritical phase with a temperature close to the critical temperature; wherein said critical temperature is close to the ambient temperature. The plant is configured to carry out a closed thermodynamic cyclic transformation, first in one direction in a charge configuration and then in the opposite direction in a discharge configuration, between said casing and said tank; wherein in the charge configuration the plant stores heat and pressure and in the discharge configuration generates energy.

An energy storage plant includes a casing for the storage of a working fluid other than atmospheric air, in a gaseous phase and in equilibrium of pressure with the atmosphere; a tank for the storage of said working fluid in a liquid or supercritical phase with a temperature close to the critical temperature; wherein said critical temperature is close to the ambient temperature. The plant is configured to carry out a closed thermodynamic cyclic transformation, first in one direction in a charge configuration and then in the opposite direction in a discharge configuration, between said casing and said tank; wherein in the charge configuration the plant stores heat and pressure and in the discharge configuration generates energy.

The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

A power generation system for a nuclear reactor includes an externally-heated turbine engine, a reactor heat exchanger, and a heat recuperating system. The externally-heated turbine engine produces compressed air that is heated by the reactor heat exchanger. The heat recuperating system includes a heat exchanger thermally connected to the externally-heated turbine engine to transfer heat to the compressed air to supplement the reactor heat exchanger.

A subcritical pressure high-temperature steam power plant includes a combustion boiler system, steam turbine generator system, and condensate and feedwater system and wherein the conditions of steam generated in the boiler system and supplied to the steam turbine generator system are subcritical pressure and high temperature (turbine inlet temperature of 593° C. or more).

A method for converting thermal energy into mechanical energy in a thermodynamic cycle includes placing a thermal energy source in thermal communication with a heat exchanger arranged in a working fluid circuit containing a working fluid (e.g., sc-CO2) and having a high pressure side and a low pressure side. The method also includes regulating an amount of working fluid within the working fluid circuit via a mass management system having a working fluid vessel, pumping the working fluid through the working fluid circuit, and expanding the working fluid to generate mechanical energy. The method further includes directing the working fluid away from the expander through the working fluid circuit, controlling a flow of the working fluid in a supercritical state from the high pressure side to the working fluid vessel, and controlling a flow of the working fluid from the working fluid vessel to the low pressure side.

An organic Rankine cycle system (100, 110, 120) with direct exchange and in cascade comprising a high temperature organic Rankine cycle (10) which carries out the direct heat exchange with a hot source (H) and a low temperature organic Rankine cycle (10′) in thermal communication with the high temperature cycle (10). The organic Rankine cycle system (100, 110, 120) is configured in a way that the thermal communication between the cycles (10, 10′) takes place through at least one heat exchanger (3) configured to use at least the condensation heat of the high temperature cycle to vaporize and/or preheat the working fluid of the low temperature organic Rankine cycle fluid and through a heat exchanger (4) configured to operate as working fluid sub-cooler for the high temperature organic Rankine cycle (10) and as a working fluid preheater for the low temperature organic Rankine cycle (10′).

The present disclosure provides pumped thermal energy storage systems that can be used to store electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby network input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in network output. Systems of the present disclosure can employ solar heating for improved storage efficiency.