Thermocline arrays comprising a plurality of pressure vessels that are in used in place of heat exchangers in a closed thermodynamic cycle system, such as a closed Brayton cycle power generation or energy storage system. Each pressure vessel is configurable to be connected to the working fluid stream or isolated from the working fluid stream.

A solar thermal power generation system includes a solar heat collection system that generates superheated steam by solar heat, a main power generation system that performs power generation by part of the superheated steam generated by the solar heat collection system, a solar heat storage/release system that stores heat in a heat storage medium or releases the heat stored in the heat storage medium, and a secondary power generation system that performs power generation by saturated steam generated by the heat storage or the heat release in the solar heat storage/release system. The solar heat storage/release system includes a heat storage heater for exchanging heat between the rest of the superheated steam generated by the solar heat collection system and the heat storage medium to store heat in the heat storage medium and to generate saturated steam, a low-temperature tank for containing the heat storage medium to be supplied to the heat storage heater, and a high-temperature tank for containing the heat storage medium after the heat storage in the heat storage heater. The secondary power generation system includes a saturated steam turbine into which the saturated steam generated by the heat storage heater can be introduced.

A solar thermal power generation system includes a solar heat collection system that generates superheated steam by solar heat, a main power generation system that performs power generation by part of the superheated steam generated by the solar heat collection system, a solar heat storage/release system that stores heat in a heat storage medium or releases the heat stored in the heat storage medium, and a secondary power generation system that performs power generation by saturated steam generated by the heat storage or the heat release in the solar heat storage/release system. The solar heat storage/release system includes a heat storage heater for exchanging heat between the rest of the superheated steam generated by the solar heat collection system and the heat storage medium to store heat in the heat storage medium and to generate saturated steam, a low-temperature tank for containing the heat storage medium to be supplied to the heat storage heater, and a high-temperature tank for containing the heat storage medium after the heat storage in the heat storage heater. The secondary power generation system includes a saturated steam turbine into which the saturated steam generated by the heat storage heater can be introduced.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

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 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.

A steam power plant and method for operation the steam power plant is provided, that comprises: a main water-steam-cycle with a high pressure (HP) steam turbine, an intermediate pressure (IP) steam turbine and a low pressure (LP) steam turbine, a condenser, and a feed water tank, wherein low pressure heaters are arranged between said condenser and said feed water tank and wherein a plurality of high pressure heaters are arranged downstream of said feed water tank, whereby said low pressure heaters, said feed water tank and said plurality of high pressure heaters are supplied with steam from a plurality of extractions at said steam turbines.

A steam power plant and method for operation the steam power plant is provided, that comprises: a main water-steam-cycle with a high pressure (HP) steam turbine, an intermediate pressure (IP) steam turbine and a low pressure (LP) steam turbine, a condenser, and a feed water tank, wherein low pressure heaters are arranged between said condenser and said feed water tank and wherein a plurality of high pressure heaters are arranged downstream of said feed water tank, whereby said low pressure heaters, said feed water tank and said plurality of high pressure heaters are supplied with steam from a plurality of extractions at said steam turbines.

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.