The present invention to provide a method of operating a thermal energy storage device comprising a body of heat transfer fluid, said body of heat transfer fluid comprising an upper temperature region comprising heat transfer fluid having a temperature above a upper threshold temperature, a lower temperature region comprising heat transfer fluid having a temperature below a lower threshold temperature and a thermocline region separating the upper and lower temperature regions and comprising heat transfer fluid having a temperature above a lower threshold temperature and below an upper threshold temperature, wherein during charging of the thermal energy storage device, heat transfer fluid is removed from the thermocline region of the body of heat transfer fluid and when the temperature of the heat transfer fluid being removed from the thermocline region of the body of heat transfer fluid rises above a maximum temperature, said heat transfer fluid being removed is brought to a temperature equal to or below said maximum temperature, wherein the maximum temperature is above the lower threshold temperature and/or wherein during discharging of the thermal energy storage device, heat transfer fluid is removed from the thermocline region of the body of heat transfer fluid and when the temperature of the heat transfer fluid being removed from the thermocline region of the body of heat transfer fluid falls below a minimum temperature, said heat transfer fluid being removed is brought to a temperature equal to or above said minimum temperature, wherein said minimum temperature is below the upper threshold temperature.

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.

The power plant system includes a molten salt reactor assembly, a thermocline unit, phase change heat exchangers, and process heat systems. The thermocline unit includes an insulated tank, an initial inlet, a plurality of zone outlets, and a plurality of gradient zones corresponding to each zone outlet and being stacked in the tank. Each gradient zone has a molten salt portion at a portion temperature corresponding to the molten salt supply from the molten salt reactor being stored in the tank and stratified. The molten salt portions at higher portion temperatures generate thermal energy for process heat systems that require higher temperatures, and molten salt portions at lower portion temperatures generate thermal energy for process heat systems that require lower temperatures. The system continuously pumps the molten salt supply in controlled rates to deliver the heat exchange fluid supply to perform work in the corresponding particular process heat system.

Energy storage systems include a heat source and a thermal energy storage system to store thermal energy produced by the heat source. The thermal energy storage system includes a first tank containing a first salt having a first melting temperature and a second tank containing a second salt having a second melting temperature. At least one input conduit is configured for transferring thermal energy from the heat source to the first tank and second tank. A first output conduit is in thermal communication with the first tank. A second output conduit is in thermal communication with the second tank. Additional energy storage systems include a heat booster positioned and configured to add thermal energy to a heated heat transfer fluid prior to reaching a tank containing at least one thermal storage material. Methods include transferring thermal energy from a thermal energy source to a plurality of thermal energy storage tanks.

A temperature control system is used for controlling a temperature of a control target. The system includes: a first circulation circuit through which a first heat transfer medium circulates; a second circulation circuit that is independent of the first circulation circuit and through which a second heat transfer medium circulates; and a third circulation circuit that is independent of the first circulation circuit and the second circulation circuit and through which a third heat transfer medium circulates. The third heat transfer medium has a usable temperature range wider than usable temperature ranges of the first heat transfer medium and the second heat transfer medium.

A device for flexibly separating cold and hot fluid media, including: a tank body, where the tank body is cylindrical and disposed vertically, upper and lower ends of the tank body are respectively provided with a hot fluid inlet and a cold fluid inlet to provide storage space for hot and cold fluids, at least one adsorption layer is provided on a side wall of the tank body, and the adsorption layer is made of a ferromagnetic material or iron; and a thermal insulation board, where the thermal insulation board is of a plate structure and set on a horizontal cross-section of the tank body, with a shape and area matching a horizontal cross-section of the tank body, a sealing strip is arranged along a circumferential direction of the thermal insulation board, the sealing strip is of a hollow structure, the hollow part is evenly filled with adsorption blocks.

Methods and systems for energy storage and management are provided. In various embodiments, heat pumps, heat engines and pumped heat energy storage systems and methods of operating the same are provided. In some embodiments, methods include controlling thermal properties of a working fluid by virtue of the timing of the operation of cylinder valves. Methods and systems for controlling mass flow rates and charging and discharging power independent of working fluid temperature and system state-of-charge are also provided.

A thermal storage system that includes one or more thermal storage tanks having a tank body that defines a tank cavity configured to hold a tank thermal storage medium; a heat exchanger assembly disposed in the tank cavity configured to run a flow of working thermal storage medium through the one or more thermal storage tanks so that heat exchange occurs between the flow of working thermal storage medium and the tank thermal storage medium; one or more cables that extend to one or more rooms of the building; and one or more heat exchange elements disposed within the one or more rooms configured to receive a flow of the working thermal storage medium from the one or more cables so that heat exchange occurs between the flow of the working thermal storage medium and an environment of the one or more rooms of the building.

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.

Underground thermal energy storage in a cylindrical or n-gonal prism shape with a vertical axis, comprising an inner volume for holding a liquid, an outer wall, an inner wall around the inner volume, and a filling layer between the inner wall and the outer wall. The inner wall comprises a series of modular wall parts provided with a heat exchanger for exchanging thermal energy with the liquid. The modular wall parts, arranged in rings, contact the inner volume and have an elastic sealing limiting liquid flow between the inner volume and the filling layer and taking up thermal expansion of the modular wall parts. The filling layer comprises an insulating layer designed to keep the outer wall below 30 C. when the inner volume is at least 90 C., and a structural layer for maintaining the insulating layer and the inner wall's modular wall parts in position.