Abstract: Some embodiments are directed to a hybrid combustion turbine power generation system, which includes a gas turbine integrated with an ACAES via fluid connection(s) between the compressor and turbine , to allow air to be extracted from, and injected into, the gas turbine, the ACAES including a direct TES and compressed air store , a top-up compressor being disposed between the fluid connection(s) and the direct TES and fluidly connected so that its inlet receives air extracted from the gas turbine in an extraction mode and its outlet sends air at a higher temperature and pressure towards the downstream direct TES , thereby optimising the temperature at which returning air is injected into the gas turbine in an injection mode. This may extend the operational power range of the gas turbine and address changes in the gas turbine operating conditions between injection and bleed modes.

Abstract: A thermal energy store comprising a chamber having a gas inlet and a gas outlet and a plurality of successive, downstream, gas permeable thermal storage layers disposed between them, each layer comprising gas permeable thermal storage media, the store being configured for gas flow from the gas inlet to gas outlet through the layers for transfer of thermal energy to or from the thermal storage media, wherein at least one of the layers is a valved layer provided with at least one valve operable selectively to allow or prevent at least some gas flow through that layer via the valve so as to bypass the thermal storage media. A control system may selectively alter the flow path of the gas flowing from inlet to outlet in response to the progress of a thermal front, so as to bypass thermal storage layers upstream of the thermal front, where transfer is complete, or downstream thereof, where transfer is minimal.

Abstract: Some embodiments are directed to a hybrid combustion turbine power plant including a conventional gas turbine, integrated via a fluid connection allowing air injection or extraction, with an adiabatic compressed air energy storage system (ACAES) including a direct TES (thermal energy store) and, downstream thereof, a supplementary compressor and pressure reducing device disposed in alternative pathways between the direct TES and compressed air store. The ACAES discharges air into the gas turbine via the fluid connection at a desired mass flow rate through the pressure reducing device, and charges with air via the supplementary compressor at a lower mass flow rate over a longer period of time, trickle charging allowing the use of a low power supplementary compressor. The use of a direct TES (40) efficiently returns the heat of compression. Alternatively, variable mass flow, reversible power machinery and a second TES may be provided downstream of the direct TES.

Abstract: System (2) for carrying out a gas based thermodynamic cycle in which a gas is compressed in at least one compressor (8) in one part of the cycle and is expanded in at least one expander (10) operating simultaneously in an upstream or downstream part of the cycle, wherein the change in absolute internal power with gas mass flow rate differs as between the compressor and the expander and wherein the system comprises a control system configured to make selective adjustments so as individually to control, either directly or indirectly, the respective gas mass flow rates through each of the compressor and expander. The system may be an energy storage system including a pumped heat energy storage system configured to provide independent graduated control of system pressure and output power by selective adjustment of the respective gas mass flow rates through each half-engine.

Abstract: Some embodiments are directed to a method of modulating power output of a hybrid gas turbine power plant, including a conventional (GT) gas turbine, via a fluid connection(s) allowing air injection or extraction, further including a compressed air energy storage system (CAES). Power is increased or decreased by selectively reconfiguring the GT compressor to reduce or increase its mass flow rate whilst simultaneously selectively adjusting how much air to transfer as a compensatory mass flow between the CAES and GT systems, via the fluid connection(s), temporarily minimizing any change in mass flow rate and hence operating conditions in the combustor, thereby providing improved frequency response mode wherein power is modulated to meet grid fluctuations in under ten seconds. Use of an adiabatic CAES system with a direct TES can return heat immediately and damp pressure fluctuations, and rapid bleed rates may be achieved temporarily by venting to atmosphere.

Abstract: A heat storage system (400) comprising a system gas inlet (460), a system gas outlet (470), and at least two thermal stores (401, 402) connected together in series therebetween, wherein each store comprises a chamber having a gas inlet (461,462), a gas outlet (471,472), and a gas-permeable thermal storage media 431 disposed therebetween, the system further comprising flow controllers (451, 452, 453, 454, 457) operatively connected to bypass passageways and so configured that, during operation, the flow path of a gas flowing through the system (400) for transfer of thermal energy to or from the storage media (431) can be selectively altered in respect of which stores (401, 402) in the series are used in response to the progress of the thermal transfer.

Abstract: Heat storage apparatus comprising at least one thermal store (300) comprising a chamber (301) having a gas inlet (306), a gas outlet (307), and a gas-permeable thermal storage media (303) disposed therebetween, the apparatus being configured such that, during operation, the flow path of a gas flowing through the chamber (301) from inlet (306) to outlet (307) for transfer of thermal energy to or from the storage media (303) can be selectively altered in response to the progress of the thermal transfer, thereby enabling the flow path to bypass inactive upstream or downstream regions of the storage media where thermal transfer is complete or minimal, so as to minimize the pressure drop across the storage media. A baffle system (305) in a main flow passageway (312) may be used to control the gas flow path.

Abstract: An apparatus (10) for compressing and expanding a gas includes a chamber (22), a positive displacement device (24) moveable relative thereto, first and second valves (26, 28) activatable to control flow of gas into and out of the chamber (22), and a controller (80) for controlling activation of the valves (26, 28) that selectively switches operation between a compression and an expansion mode with selective switching between modes being achieved by selectively changing the activation timing of at least one of the valves during the first mode. An energy storage system including the device may be operatively coupled via a rotary device for power transmission to an input/output device, whereby the direction and speed of rotation are preserved during switching, and the input/output device may be synchronized to the grid.

Abstract: Apparatus (1) for storing energy includes a high pressure storage vessel (10) for receiving high pressure gas, the high pressure storage vessel (10) including a high pressure heat store including a first chamber housing a first gas-permeable heat storage structure (14); and a low pressure storage vessel (11,12) for receiving low pressure gas, the low pressure storage vessel (11,12) including a low pressure heat store including a second chamber housing a second gas-permeable heat storage structure (16,18. The first heat storage structure (14) has a mean surface area per unit volume which is higher than a mean surface area per unit volume of the second heat storage structure (16,18).

Abstract: A system includes a primary, combustion turbine based system that includes one or more power shaft assemblies including a generator or motor/generator, a compressor and an expansion turbine associated with the one or more power shaft assemblies, and a combustor to feed the expansion turbine. The primary system includes a first flow network allowing outlet air from the compressor to pass downstream to the combustor for combustion and the expansion turbine for expansion. The primary system is modified by integration of an adiabatic compressed air energy storage sub-system that includes a compressed air store and a thermal energy storage system for removing and returning thermal energy to the compressed air upon charging and discharging the store. The sub-system includes a second flow network allowing outlet air from the compressor to pass, upon charging, to the compressed air store, and to pass, upon discharging, back to the combustor and/or expansion turbine.

Abstract: In an energy storage and recovery system, working fluid from a first vessel is compressed by power machinery and passes, via a regenerator, into a second vessel, where it is forced to condense, the temperature and pressure of the saturated working liquid/vapour mixture continuously rising during storage. The stored energy is recovered by the vapour returning through the regenerator and power machinery where it expands to produce work before condensing back into the first vessel. The regenerator comprises a gas permeable, solid thermal storage medium which, during storage, stores superheat and some latent heat from the vapour passing through it in respective downstream regions that exhibit continuously increasing temperature profiles during storage and a small temperature difference with the surrounding vapour, thereby minimising irreversible losses during the thermal energy transfers.

Abstract: System (2) for carrying out a gas based thermodynamic cycle in which a gas is compressed in at least one compressor (8) in one part of the cycle and is expanded in at least one expander (10) operating simultaneously in an upstream or downstream part of the cycle, wherein the change in absolute internal power with gas mass flow rate differs as between the compressor and the expander and wherein the system comprises a control system configured to make selective adjustments so as individually to control, either directly or indirectly, the respective gas mass flow rates through each of the compressor and expander. The system may be an energy storage system including a pumped heat energy storage system configured to provide independent graduated control of system pressure and output power by selective adjustment of the respective gas mass flow rates through each half-engine.

Abstract: A thermal energy store comprising a chamber having a gas inlet and a gas outlet and a plurality of successive, downstream, gas permeable thermal storage layers disposed between them, each layer comprising gas permeable thermal storage media, the store being configured for gas flow from the gas inlet to gas outlet through the layers for transfer of thermal energy to or from the thermal storage media, wherein at least one of the layers is a valved layer provided with at least one valve operable selectively to allow or prevent at least some gas flow through that layer via the valve so as to bypass the thermal storage media. A control system may selectively alter the flow path of the gas flowing from inlet to outlet in response to the progress of a thermal front, so as to bypass thermal storage layers upstream of the thermal front, where transfer is complete, or downstream thereof, where transfer is minimal.

Abstract: Apparatus for use as a heat pump includes compression chamber means, inlet means for allowing gas to enter the compression chamber means, compression means for compressing gas contained in the compression chamber means, heat exchanger means for receiving thermal energy from gas compressed by the compression means, expansion chamber means for receiving gas after exposure to the heat exchange means, expansion means for expanding gas received in the expansion chamber means, and exhaust means for venting gas from the expansion chamber means after expansion thereof.

Abstract: An apparatus for storing energy includes a compression chamber for receiving a gas, a compression piston for compressing gas contained in the compression chamber, a first heat store for receiving and storing thermal energy from gas compressed by the compression piston, an expansion chamber for receiving gas after exposure to the first heat store, an expansion piston for expanding gas received in the expansion chamber, and a second heat store for transferring thermal energy to gas expanded by the expansion piston. The cycle used by the apparatus has two different stages that can be split into separate devices or combined into one device.

Abstract: Apparatus (10) for storing energy, comprising: compression chamber means (24) for receiving a gas; compression piston means (25) for compressing gas contained in the compression chamber means; first heat storage means (50) for receiving and storing thermal energy from gas compressed by the compression piston means; expansion chamber means (28) for receiving gas after exposure to the first heat storage means; expansion piston means (29) for expanding gas received in the expansion chamber means; and second heat storage means (60) for transferring thermal energy to gas expanded by the expansion piston means. The cycle used by apparatus (10) has two different stages that can be split into separate devices or combined into one device.

Abstract: Heat storage apparatus comprising at least one thermal store (300) comprising a chamber (301) having a gas inlet (306), a gas outlet (307), and a gas-permeable thermal storage media (303) disposed therebetween, the apparatus being configured such that, during operation, the flow path of a gas flowing through the chamber (301) from inlet (306) to outlet (307) for transfer of thermal energy to or from the storage media (303) can be selectively altered in response to the progress of the thermal transfer, thereby enabling the flow path to bypass inactive upstream or downstream regions of the storage media where thermal transfer is complete or minimal, so as to minimise the pressure drop across the storage media. A baffle system (305) in a main flow passageway (312) may be used to control the gas flow path.

Abstract: A heat storage system (400) comprising a system gas inlet (460), a system gas outlet (470), and at least two thermal stores (401, 402) connected together in series therebetween, wherein each store comprises a chamber having a gas inlet (461,462), a gas outlet (471,472), and a gas-permeable thermal storage media 431 disposed therebetween, the system further comprising flow controllers (451, 452, 453, 454, 457) operatively connected to bypass passageways and so configured that, during operation, the flow path of a gas flowing through the system (400) for transfer of thermal energy to or from the storage media (431) can be selectively altered in respect of which stores (401, 402) in the series are used in response to the progress of the thermal transfer.

Abstract: A valve includes a first pan defining a first array of apertures (20?) and a second part (50) defining a second array of apertures (60?), the first pan (10?) being moveable relative to the second part (50) between a first configuration in which passage of a fluid through the valve is substantially prevented and a second configuration in which passage of fluid is allowed. In one embodiment, the first pan (10?) includes a flexible plate-like member configured to engage a sealing face of the second part (50) when in the second configuration and lock in the second configuration in response to a pressure differential across the valve. The plate-like member is sufficiently flexible to conform to a profile of the sealing face in response to a pressure differential across the valve.

Abstract: A valve comprising a first pan (10?) defining a first array of apertures (20?) and a second part (50) defining a second array of apertures (60?), the first pan (10?) being moveable relative to the second part (50) between a first configuration in which passage of a fluid through the valve is substantially prevented and a second configuration in which passage of fluid is allowed. In one embodiment, the first pan (10?) comprises a flexible plate-like member configured to engage a sealing face of the second part (50) when in the second configuration and lock in the second configuration in response to a pressure differential across the valve. The plate-like member is sufficiently flexible to conform to a profile of the sealing face in response to a pressure differential across the valve.