A method is provided for converting heat from a heat source to mechanical energy. The method comprises heating a working fluid using heat supplied from the heat source; and expanding the heated working fluid to lower pressure of the working fluid and generating mechanical energy as the pressure of the working fluid is lowered. The method is characterized by using a working fluid comprising (2E)-1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)pent-2-ene (HFO-153-10mzzy). Also provided is a power cycle apparatus. The apparatus is characterized by containing a working fluid comprising HFO-153-10mzzy.

A method is provided for converting heat from a heat source to mechanical energy. The method comprises heating a working fluid using heat supplied from the heat source; and expanding the heated working fluid to lower pressure of the working fluid and generating mechanical energy as the pressure of the working fluid is lowered. The method is characterized by using a working fluid comprising (2E)-1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)pent-2-ene (HFO-153-10mzzy). Also provided is a power cycle apparatus. The apparatus is characterized by containing a working fluid comprising HFO-153-10mzzy.

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.

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.

A power plant comprises supplies of hydrogen fuel, oxygen fuel and water, a boiler comprising a burner for combusting hydrogen and oxygen to produce heat, combustion products and low/intermediate-pressure steam and a first heat exchanger configured to heat water to generate high-pressure steam, and a steam turbine comprising a first turbine configured to be driven only with the high-pressure steam to provide input to a first electrical generator and a second turbine configured to be driven by low/intermediate-pressure steam from the boiler. A method of operating a steam plant comprises combusting hydrogen fuel in a boiler to produce combustion products and LP/IP steam, turning a turbine with the combustion products, condensing water from the combustion products in a condenser, heating water from the condenser in a heat exchanger within the boiler to produce HP steam and turning a turbine with the steam from the first heat exchanger.

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.

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.

A closed loop thermal cycle expander bypass flow control is described. An expander is positioned within and surrounded by a housing to receive a working fluid and rotate in response to expansion of the working fluid flowing through the expander. A bypass channel is positioned within and surrounded by the housing to define a fluid flow path that bypasses the expander. A fluid flow control sub-assembly is fluidically coupled to the expander and the bypass channel, and attached to the housing. The fluid flow control sub-assembly can receive the working fluid at a housing inlet and either flow the working fluid through the expander and block the working fluid from flowing through the bypass channel, or flow the working fluid through the housing bypassing the expander, flow the working fluid out via a housing outlet, and block the working fluid from flowing through the expander.

A closed loop thermal cycle expander bypass flow control is described. An expander is positioned within and surrounded by a housing to receive a working fluid and rotate in response to expansion of the working fluid flowing through the expander. A bypass channel is positioned within and surrounded by the housing to define a fluid flow path that bypasses the expander. A fluid flow control sub-assembly is fluidically coupled to the expander and the bypass channel, and attached to the housing. The fluid flow control sub-assembly can receive the working fluid at a housing inlet and either flow the working fluid through the expander and block the working fluid from flowing through the bypass channel, or flow the working fluid through the housing bypassing the expander, flow the working fluid out via a housing outlet, and block the working fluid from flowing through the expander.

A turbine of an organic Ranking cycle ORC is described, the turbine comprising a shaft supported by bearings and a plurality of seals arranged round the shaft for confining the operating fluid expanding in the turbine. The seals define at least four axially consecutive chambers. The operating fluid, with function of barrier fluid, is fed into one of the chambers adjacent to turbine stages; a gas, preferably inert, is fed into one of the chambers adjacent to the bearings, and the corresponding seals are gas seals. This configuration prevents the operating fluid from any kind of contamination by the lubricant used for the bearings, and avoids polluting the environment.