A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

Embodiments of the present disclosure are directed toward systems and method for cooling a refrigerant flow of a refrigerant circuit with a cool water flow from a cool water storage to generate a warm water flow and to cool the refrigerant flow by a subcooling temperature difference, flowing the warm water flow to the cool water storage, and thermally isolating the warm water flow from the cool water flow in the cool water storage.

A heat accumulator device for accumulating sensible heat in molten salts, including: -a heat accumulator vessel for receiving molten salt, a separating layer being disposed in the heat accumulator vessel in order to separate a cold region, in which cold molten salt is present, from a hot region, in which hot molten salt is present, and the cold region being located below the hot region; - a device for loading and unloading the heat accumulator vessel, which device is connected to the cold region and to the hot region; and - a volume compensation device for compensating a temperature-related change in the volume of the molten salt, the volume compensation device interacting with the cold region and/or with the separating layer.

A thermal energy storage system for comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a plurality of vessels to store the working fluid. Each vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessels and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessels. The vessels are arranged in parallel.

A floating piston configured to be disposed in a vessel of a thermal energy storage system to separate a hot working fluid from a cold working fluid. The floating piston includes a piston body having a first end, a second end, and a central region. There is a compressible member which is disposed in the central region of the piston and which is configured to engage with an inner surface of the vessel when the piston is disposed in the vessel.

The disclosed technology includes systems and methods of managing temperature distributions of phase change material. The disclosed technology can include a system comprising a platform having a passageway therethrough. The platform can include a density that is less than a density of the phase change material when in a solid phase and greater than a density of the phase change material when in a liquid phase. The system can further include a whip rod disposed at least partially in the passageway of the platform.

An enclosed storage tank for the simultaneous addition and removal, and storage, of two liquid layers of different density has a bottom wall, a cylindrical side wall, a roof, and a central column extending from the bottom wall to the roof. An upper perforated flexible tensile fabric diaphragm is disposed in the upper portion of the tank, and a low-density liquid conduit extends from outside the tank into communication with the upper portion of the tank above the upper diaphragm. A lower perforated flexible tensile fabric diaphragm is disposed in the lower part of the tank, and a high-density liquid conduit extends from outside the tank shell into communication with the lower portion of the tank below the lower liquid diaphragm. The diaphragms minimize internal mixing through thermoclines as liquid is introduced into and/or discharged from the tank, and reduce overall costs of tank installations and operations.

A thermal energy storage system comprising a working fluid to store and transfer thermal energy between a heat source and a thermal load and a vessel to store the working fluid. The vessel has an interior region and a floating separator piston in the interior region to separate a hot portion from a cold portion of the working fluid. There is a first manifold thermally coupled to an output of the heat source and to an input of the thermal load and fluidly coupled to the interior region of the vessel and a second manifold thermally coupled to an input of the heat source and an output of the thermal load and fluidly coupled to the interior region of the vessel. There is a controller configured to maintain the working fluid in a liquid state.

A nuclear facility has a fuel pool containing a liquid and an associated cooling circuit for a circulating cooling agent. The cooling circuit contains a cooling module with a first heat exchanger which immerges into the liquid, a second heat exchanger which is located outside the fuel pool, and connecting lines between the first exchanger and the second heat exchanger. In order to provide for reliable cooling even if a filling level drops, the cooling module contains a lifting body and floats in the liquid such that its altitude varies with the filling level of the liquid in the fuel pool.

An energy storage device for temporarily storing thermal energy includes a closed storage circuit, to which heat can be supplied by a heat source and from which heat can be withdrawn by a heat consumer. A fluid container is divided into a first fluid storage chamber for colder fluid and a second fluid storage chamber for warmer fluid by a displaceable separating element. At least one pump for conveying fluid from the first fluid storage chamber into the second fluid storage chamber, and/or vice versa, is provided in the storage circuit. A power plant including the energy storage device and a method for operating the energy storage device is also provided.