A plant for storing and discharging thermal energy comprises a first heat exchanger coupled to a heat source, a second heat exchanger coupled to a heat user, a fluid configured to store thermal energy, a storage device for the fluid, a circuit configured to couple the first heat exchanger, the second heat exchanger and the storage device. The storage device comprises N+B storage sections fluidly connected to each other, where N is equal to or greater than two and B is less than N; each of the N+B storage sections has a same containment volume. The fluid occupies a volume substantially equal to N times the containment volume. A separation gas is inserted in the storage device, is in contact with the fluid and is configured to always keep separate a hot portion of the fluid from a cold portion of the same fluid.

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.

Methods and systems are provided for regulating the temperature of rear axle lubrication oil. In one example, a rear axle coolant system may include a coolant loop with a plurality of valves and sensors, regulating the coolant flow in heat exchange relationship with an exhaust gas heat recovery and storage system to deliver warm coolant to a rear axle heat exchanger to warm the rear axle lubrication oil. The method may regulate the components of the rear axle coolant system through a controller, receiving sensor input from the components of the coolant system.

High temperature thermal energy storage, distinctive in that the storage comprises: a thermally insulated foundation, at least one self-supported cassette arranged on said foundation, which cassette is a self-supporting frame or structure containing a number of concrete thermal energy storage elements, some or all of said elements comprising embedded heat exchangers, a pipe system, the pipe system comprising an inlet and an outlet for thermal input to and output from the storage, respectively, and connections to said heat exchangers for circulating fluid through said heat exchangers for thermal energy input to or output from said thermal energy storage elements, and thermal insulation around and on top of the at least one self-supported cassette with concrete thermal storage elements. The invention also provides a method of building and methods of operating the storage.

A heat storage device of the present disclosure includes a latent heat storage material and a container. The latent heat storage material is water-soluble. The container houses the latent heat storage material and is formed of a main material being aluminum or an aluminum alloy. The container has a joining portion and a first coating. The first coating covers at least the joining portion on an inner surface of the container. On a surface of the first coating, a first element and fluorine are present. The first element is an element other than aluminum and having a lower ionization tendency than potassium.

The disclosed technology includes methods of extracting geothermal energy, generally comprising the steps of: insertion of a thermal mass into a Heat Absorption Zone, absorbing heat in thermal mass, raising the thermal mass to a Heat Transfer Zone, and transferring the heat from the thermal mass. The acquired heat can be used to generate electricity or to drive an industrial process. The thermal mass can have internal chambers containing a liquid such as molten salt, and can also have structures facilitating heat exchange using a thermal exchange fluid, such as a gas or a glycol-based fluid. In some embodiments, two thermal masses are used as counterweights, reducing the energy consumed in bringing the heat in the thermal masses to the surface. In other embodiments, solid or molten salt can be directly supplied to a well shaft to acquire geothermal heat and returned to the surface in a closed loop system.

There is provided a system for energy storage comprising: a fluidized bed apparatus with an energy storage material, wherein the energy storage material is provided in volumes coated with an outer layer of solid particles of a different material, wherein the volumes have a largest size in the interval 1-1000 μm and wherein the solid particles (5) have a largest size in the interval 1-500 nm. Advantages of the system include that structural changes in the energy storage material over time are minimized so that the energy storage material can be used over many cycles without any noticeable impairment. The heat transfer to and from the energy storage material is improved. The system can further be used for CO.sub.2 capture.

A thermal storage subsystem may include at least a first storage reservoir configured to contain a thermal storage liquid at a storage pressure that is greater than atmospheric pressure. A liquid passage may have an inlet connectable to a thermal storage liquid source and configured to convey the thermal storage liquid to the liquid reservoir. A first heat exchanger may be provided in the liquid inlet passage and may be in fluid communication between the first compression stage and the accumulator, whereby thermal energy can be transferred from a compressed gas stream exiting a gas compressor/expander subsystem to the thermal storage liquid.

The present application pertains in some embodiments to a thermal storage system. The system may include, for example, a warm thermal storage region; a cold thermal storage region; and a physical divider. The warm thermal storage region may include at least two liquid phases. The cold thermal storage region may include at least one liquid phase. The physical divider substantially separates the warm thermal storage region from the cold thermal storage region.

System and method utilizing thermochemical energy storage for abatement of volatile organic compounds (VOCs) are provided. The system includes a thermochemical energy storage module cyclically operable in a discharging cycle and in a charging cycle. Abatement of VOCs may be performed in either cycle. Disclosed embodiments are expected to provide a zero-added carbon VOC abatement system that in certain situations can operate uninterruptedly 24/7 with the flexibility to facilitate consumption of energy during periods of inexpensive rates for electricity.