Systems and methods for variable pressure inventory control of a closed thermodynamic cycle power generation system or energy storage system, such as a reversible Brayton cycle system, with at least a high pressure tank and an intermediate pressure tank are disclosed. Operational parameters of the system such as working fluid pressure, turbine torque, turbine RPM, generator torque, generator RPM, and current, voltage, phase, frequency, and/or quantity of electrical power generated and/or distributed by the generator may be the basis for controlling a quantity of working fluid that circulates through a closed cycle fluid path of the system.

Systems and methods relating to variable pressure turbines are disclosed. A power generation system may include a closed cycle system configured to generate power, a combustor, and a control system. The closed cycle system may include a working fluid circulating in a closed cycle path. The combustor may provide thermal energy to the working fluid. Further, the control system may be configured to determine to increase an amount of power generated by the closed cycle system, and in response to the determination to increase the amount of power generated by the closed cycle system, cause an increase in pressure of the working fluid in the closed cycle path.

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.

Systems and methods for variable pressure inventory control of a closed thermodynamic cycle power generation system or energy storage system, such as a reversible Brayton cycle system, with at least a high pressure tank and an intermediate pressure tank are disclosed. Operational parameters of the system such as working fluid pressure, turbine torque, turbine RPM, generator torque, generator RPM, and current, voltage, phase, frequency, and/or quantity of electrical power generated and/or distributed by the generator may be the basis for controlling a quantity of working fluid that circulates through a closed cycle fluid path of the system.

An improved closed loop Brayton cycle for a power plant is provided that includes a heater, at least one turbine, a recuperator, at least one cooler, at least one compressor, a bypass line and a flap valve arrangement in a closed circuit in which working fluid is circulated to produce electricity via a generator. Depending upon the requirement, such as, in case of gird load disconnection, speed of a shaft-line to which the turbine, the compressor and the generator are configured is also required to be reduced without any impact on the pressure drop in the cycle. For that the non-tight flap valve arrangement is configured on each conduit between the heater and the at least one turbine in a closest possible proximity to each turbine inlet.

Electrical power systems, including generating capacity of a gas turbine, where additional power is generated from an air expander and gas turbine simultaneously from a stored compressed air and thermal system.

A turbomachinery control system for controlling supercritical working fluid turbomachinery. The control system includes a light emitter to project light through working fluid of the turbomachinery toward a primary light detector provided within a line of sight to the emitter. The system further includes one or more secondary light detectors spaced from the line of sight, and a controller determining one or both of an intensity of light detected by the primary detector relative to the detected light intensity by the secondary detector, and wavelength of light detected by the primary detector relative to wavelength of light detected by the secondary detector. The controller determines the working fluid proximity of the critical point based on one or both of the determined relative intensity and determined relative wavelength, and controlling an actuator to control turbomachinery inlet or outlet conditions in accordance with the working fluid determined proximity of the critical point.

A supercritical working fluid closed cycle heat engine includes, in fluid flow series: a heat source heat exchanger configured to raise the temperature of a working fluid; an expander configured to extract work from the working fluid; a condenser configured to exchange heat between the working fluid and the cooling medium;
and a separator configured to separate liquid phase working fluid from gaseous phase working fluid and deliver gaseous phase working fluid to a gaseous compressor and liquid phase working fluid to a fixed displacement liquid pump, the compressor and pump being arranged in parallel. Each of the compressor and fixed displacement pump are configured to return fluid to the heat source heat exchanger. The compressor comprises a variable inlet guide vane and a variable outlet diffuser vane.

A supercritical working fluid closed cycle heat engine includes, in fluid flow series: a heat source heat exchanger configured to raise the temperature of a working fluid; an expander configured to extract work from the working fluid; a condenser configured to exchange heat between the working fluid and the cooling medium; and a separator configured to separate liquid phase working fluid from gaseous phase working fluid and deliver gaseous phase working fluid to a gaseous compressor and liquid phase working fluid to a fixed displacement liquid pump, the compressor and pump being arranged in parallel. Each of the compressor and fixed displacement pump are configured to return fluid to the heat source heat exchanger. The compressor comprises a variable inlet guide vane and a variable outlet diffuser vane.

Disclosed is an apparatus, system, and method, by which a difference in the thermal energies, and/or temperatures, of two bodies, materials, gases, liquids, solids, objects, and/or other groups or collections of matter, may be harnessed to provide mechanical energy to a rotary engine and/or shaft. Also disclosed is an apparatus, system, and method, by which mechanical energy (e.g., the rotation of a shaft) may be used to produce and/or amplify a difference in the thermal energies, and/or temperatures of, and/or between, two bodies, materials, gases, liquids, solids, objects, and/or other groups or collections of matter. The disclosed thermal-to-mechanical energy conversion apparatus, as well as the complementary mechanical-to-thermal energy conversion apparatus, lacks moving parts and therefore satisfies a previously unmet need for a simple, robust, and efficient heat engine.