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.

A process of forming an aerofoil is provided. The process includes: providing a layered, planar pre-form; inflating and hot creep forming the pre-form to form an intermediate structure having aerofoil pressure and suction surfaces, and a front, edge-receiving portion joining front edges of the pressure and suction surfaces; providing a leading edge piece; and bonding the leading edge piece to the front, edge-receiving portion of the intermediate structure to form an aerofoil in which the leading edge piece forms an aerofoil leading edge.

A power generation facility in an embodiment includes: a boiler; a high-pressure turbine to which steam generated in the boiler is introduced; a low-pressure turbine provided downstream of the high-pressure turbine; and a condenser that condenses steam discharged from the low-pressure turbine. The power generation facility further includes: a feed pipe that leads feedwater in the condenser to the boiler; a heat storage and steam generation device that has a heat storage function that uses surplus energy generated in an own system to store heat, and a steam generation function that has part of feedwater led by the feed pipe introduced thereinto and turns the feedwater into steam by the stored heat; and a steam supply pipe that supplies steam generated in the heat storage and steam generation device to an own system.

A power generation facility in an embodiment includes: a boiler; a high-pressure turbine to which steam generated in the boiler is introduced; a low-pressure turbine provided downstream of the high-pressure turbine; and a condenser that condenses steam discharged from the low-pressure turbine. The power generation facility further includes: a feed pipe that leads feedwater in the condenser to the boiler; a heat storage and steam generation device that has a heat storage function that uses surplus energy generated in an own system to store heat, and a steam generation function that has part of feedwater led by the feed pipe introduced thereinto and turns the feedwater into steam by the stored heat; and a steam supply pipe that supplies steam generated in the heat storage and steam generation device to an own system.

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 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.

A power plant having a steam circuit which can be supplied, in the region of a heat recovery steam generator, with thermal energy for producing steam, the steam circuit has, in the region of the heat recovery steam generator, a high pressure part, a medium pressure part and a low pressure part. In addition, a heat reservoir which has a phase change material and which is not situated in the region of the heat recovery steam generator is included, wherein, in order to supply the heat reservoir with thermally processed water, a supply line which leads out from the high pressure part or the medium pressure part is included and a discharge line which leads into the medium pressure part, the low pressure part or a steam turbine is included for discharging thermally processed water from the heat reservoir.

A power plant having a steam circuit which can be supplied, in the region of a heat recovery steam generator, with thermal energy for producing steam, the steam circuit has, in the region of the heat recovery steam generator, a high pressure part, a medium pressure part and a low pressure part. In addition, a heat reservoir which has a phase change material and which is not situated in the region of the heat recovery steam generator is included, wherein, in order to supply the heat reservoir with thermally processed water, a supply line which leads out from the high pressure part or the medium pressure part is included and a discharge line which leads into the medium pressure part, the low pressure part or a steam turbine is included for discharging thermally processed water from the heat reservoir.

An energy storage device having: a high-temperature regenerator containing a solid, particularly porous storage material (S); a working gas (A) as the heat transfer medium to transfer heat between the storage material (S) and the working gas (A) flowing through; and a charging circuit and a discharging circuit for the working gas (A). The charging circuit is designed such that starting from a pre-heating unit at least one first heat transfer duct of a recuperator, a first compressor (HO), the high-temperature regenerator, a second heat transfer duct of the recuperator and then a first expander are interconnected, thus forming a circuit, so as to conduct fluid. The first compressor is coupled with the first expander, and the first compressor forms part of a first piston machine (K1) and the first expander forms part of a second piston machine (K2), the piston machines (K1, K2) being operable either as a compressor or as an expander such that the first compressor of the charging circuit forms a second expander in the discharging circuit and that the first expander of the charging circuit forms a second compressor in the discharging circuit. The high-temperature regenerator can be connected to either the charging circuit or the discharging circuit to conduct fluid and can be controlled such that the high-temperature regenerator, the compressor and the expander form either part of the charging circuit or part of the discharging circuit. The charging circuit, the discharging circuit and the high-temperature regenerator have the same working gas (A) so that the working gas (A) comes into direct contact with the storage material of the high-temperature regenerator both in the charging circuit and in the discharging circuit.

The present disclosure provides pumped thermal energy storage systems that can be used to store and extract electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby net work 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 net work output.