Device, plant and method with high level of energy efficiency for storing and use of thermal energy of solar origin

Abstract

A device for storing and releasing heat energy for an electrical power production plant is described. The device has: at least one bed of fluidisable particles, arranged at least partly at receiving surfaces for such radiation; means for feeding a fluidisation gas for the fluidisation of said particles; and heat exchange elements flown through, in use, by an operating fluid and arranged at or in proximity of said bed of fluidisable particles.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an industrial plant based on the use and storage of solar energy, to a device for storing and releasing solar thermal energy suitable for use within said plant and to a related method.BACKGROUND OF THE INVENTION[0002]It is known the use of solar energy concentrated through heliostats, fixed or by tracking. It also known the possibility of storing not used heat in solid materials with high thermal conductivity (typically graphite) for later use. For the exploitation of heat is normally used a heat exchanger which can also be immersed in the storage material and crossed by a working fluid—typically water, steam or other carriers—capable to absorb and transport heat energy contained therein.[0003]As storage systems, such as graphite, are able to reach high temperatures (even 2000° C.), the limit of technology is set out by the thermal resistance of the metal tube bundles in charge for heat removal.[0004]In addition, the stora...

AI Technical Summary

Benefits of technology

The invention is a system for efficiently producing and storing solar thermal energy using a fluidisable granular bed that can play both roles. This system minimizes stress on heat exchangers and increases efficiency of heat exchange to the working fluid. By separating the storing and releasing steps, the system becomes more versatile and efficient. The system includes two fluidisable beds, one for storing and one for exchange with the working fluid, and uses air from the environment as the fluidizing gas. The hot air from the fluidised beds is sent to an air-air exchanger to release its heat to the cold fluidizing air. This invention allows for maximum energy recovery and is particularly suitable for solar energy plants.

Problems solved by technology

), the limit of technology is set out by the thermal resistance of the metal tube bundles in charge for heat removal.

In addition, the storage in solids does not allow—for the thermal inertia of the same and for the low thermal diffusivity values—to follow the trend of the required power as atmospheric conditions and day-night cycles vary.

Based on the foregoing, therefore, a difficulty of the known systems is related to the low efficiency due to the limited maximum temperatures reachable and their lack of flexibility to follow the trend of the load as atmospheric conditions vary.

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