A method for heat treating metal alloy powder includes (a) introducing metal alloy powder to a chamber having a floor and a sidewall; (b) flowing a fluidizing gas through the floor and into the chamber to fluidize the metal alloy powder in the chamber; (c) flowing an additional gas through the sidewall into the chamber; and (d) heating the chamber to heat treat the metal alloy powder in the chamber. A system for heat treating metal alloy powder includes an inner chamber having a porous floor and a porous sidewall; an outer chamber, the inner chamber being inside of the outer chamber and defining an annular space between the outer chamber and the inner chamber, wherein the outer chamber and the inner chamber are inside a furnace; a source of fluidizing gas connected to the porous floor through the annular space; and a source of additional gas communicated with the porous sidewall through the annular space.

The present disclosure is directed to systems and methods that transfer heat directly from hot particles to a cold fluid, such as sCO.sub.2, by bringing the hot particles and cold fluid into direct contact at the operating pressure of the cold fluid. These systems and methods can both stand-off large pressure differentials while allowing particles to pass through and limiting cold fluid leakage either continuously or through a batch process.

The present disclosure is directed to systems and methods that transfer heat directly from hot particles to a cold fluid, such as sCO.sub.2, by bringing the hot particles and cold fluid into direct contact at the operating pressure of the cold fluid. These systems and methods can both stand-off large pressure differentials while allowing particles to pass through and limiting cold fluid leakage either continuously or through a batch process.

A heat storage system using sand as a solid heat storage medium has a fluidized bed heat exchanger (3) arranged between and separated from a storage tank (1) for cold sand and a storage tank (2) for hot sand by weirs (4, 5). The heat exchanger (3) is divided into a plurality of chambers (7) by weirs (6). The weirs (4, 5, 6) are arranged as a combination of overflow and underflow weirs. Fluidized sand is produced in the chambers (7) by a blower (14) positioned underneath the heat exchanger (3). Heat is transferred from a heat source to the sand fluidized and from the fluidized sand to a heat transport medium by transferring mechanisms (8, 9) in the chambers (7). The sand is redirected in a horizontal direction by horizontally acting blowers and/or installations (12) projecting into a respective chamber from a side.

A heat storage system using sand as a solid heat storage medium has a fluidized bed heat exchanger (3) arranged between and separated from a storage tank (1) for cold sand and a storage tank (2) for hot sand by weirs (4, 5). The heat exchanger (3) is divided into a plurality of chambers (7) by weirs (6). The weirs (4, 5, 6) are arranged as a combination of overflow and underflow weirs. Fluidized sand is produced in the chambers (7) by a blower (14) positioned underneath the heat exchanger (3). Heat is transferred from a heat source to the sand fluidized and from the fluidized sand to a heat transport medium by transferring mechanisms (8, 9) in the chambers (7). The sand is redirected in a horizontal direction by horizontally acting blowers and/or installations (12) projecting into a respective chamber from a side.

The present disclosure relates to particle-based thermal energy storage (TES) systems employed for the heating and cooling applications for residential and/or commercial buildings. Particle-based TES systems may store thermal energy in the particles during off-peak times (i.e., when electricity demand and/or costs are relatively low) and remove the stored thermal energy for heating or cooling applications for buildings during peak times (i.e., when electricity demand and/or costs are relatively high).

The present disclosure describes heat exchangers for converting thermal energy stored in solid particles to electricity. Electro-thermal energy storage converts off-peak electricity into heat for thermal energy storage, which may be converted back to electricity, for example during peak-hour power generation. The heat exchanger for converting thermal energy stored in solid particles to electricity enables the conversion of thermal energy into electrical energy for redistribution to the grid. In some embodiments, pressurized fluidized-bed heat exchangers may achieve efficient conversion of thermal energy to electricity by providing direct contact of the solid particles with a gas stream.

The present disclosure describes heat exchangers for converting thermal energy stored in solid particles to electricity. Electro-thermal energy storage converts off-peak electricity into heat for thermal energy storage, which may be converted back to electricity, for example during peak-hour power generation. The heat exchanger for converting thermal energy stored in solid particles to electricity enables the conversion of thermal energy into electrical energy for redistribution to the grid. In some embodiments, pressurized fluidized-bed heat exchangers may achieve efficient conversion of thermal energy to electricity by providing direct contact of the solid particles with a gas stream.

The present disclosure relates to particle-based thermal energy storage (TES) systems employed for the heating and cooling applications for residential and/or commercial buildings. Particle-based TES systems may store thermal energy in the particles during off-peak times (i.e., when electricity demand and/or costs are relatively low) and remove the stored thermal energy for heating or cooling applications for buildings during peak times (i.e., when electricity demand and/or costs are relatively high).

The present disclosure describes heat exchangers for converting thermal energy stored in solid particles to electricity. Electro-thermal energy storage converts off-peak electricity into heat for thermal energy storage, which may be converted back to electricity, for example during peak-hour power generation. The heat exchanger for converting thermal energy stored in solid particles to electricity enables the conversion of thermal energy into electrical energy for redistribution to the grid. In some embodiments, pressurized fluidized-bed heat exchangers may achieve efficient conversion of thermal energy to electricity by providing direct contact of the solid particles with a gas stream.