Device and system for the intermediate storage of thermal energy

Abstract

A device for the intermediate storage of thermal energy and to a system comprising a plurality of such devices is provided. The device has a solids store and a pipe system, which is formed of individual pipes and runs through the solids store and through which an energy carrier medium flows. In order to be able to quickly and uniformly charge the solids store with thermal energy or discharge thermal energy therefrom, heat conducting elements are provided, each forming heat transmission regions with the individual pipes and each extending into the regions of the solids store that are free of individual pipes. The heat conducting elements also have a higher heat conductivity than the solids store.

Description

[0001]This nonprovisional application is a continuation of International Application No. PCT / EP2010 / 007909, which was filed on Dec. 23, 2010, and which claims priority to German Patent Application No. DE 10 2009 060 911.3, which was filed in Germany on Dec. 31, 2009, and which are both herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a device and system for the intermediate storage of thermal energy.[0004]2. Description of the Background Art[0005]In view of the dwindling primary raw materials worldwide as resources for energy production, regenerative and alternative concepts are becoming more and more important. Examples are the use of solar energy in solar thermal power plants or the use of waste heat from industrial manufacturing processes. Because these alternative forms of energy are coupled to solar radiation or to certain industrial processes, however, their continuous availability is not guarante...

AI Technical Summary

Benefits of technology

[0014]The invention resolves this problem with the aid of heat conducting elements, which have a higher thermal conductivity compared with the material of the solid storage medium and extend proceeding from the individual pipes into the solid storage medium. Preferred materials for the heat conducting elements are metals such as, for example, steel, aluminum, copper, or graphite, which can be available both as ground or compressed natural graphite and expanded or compressed natural graphite (graphite film). The heat conducting elements in this way form flow pathways for the rapid transport of thermal energy over greater distances within the solid body, from which then a uniform loading of the storage volume occurs over only relatively short distances. This allows for a rapid and uniform charging and discharging of the solid storage medium with the best possible utilization of the storage volume. The invention is thus characterized by a high specific heat output of the solid storage medium also at relatively great radial distances of the individual pipes of the pipe system and thus combines the seemingly contradictory requirements for a high thermal conductivity, on the one hand, and a cost-effective storage material, on the other.

Problems solved by technology

In a solid storage medium made of concrete, this has the result that areas, directly surrounding the individual pipes, of the solid storage medium are charged very rapidly thermally, however, with increasing distance from the individual pipes a great temperature drop is to be observed (FIG. 12a), and therefore a relatively long time interval is necessary until a very largely equalized energy state over the entire volume of the solid storage medium has been achieved.

To shorten the charging and discharging times for the solid storage medium, the radial distance of the individual pipes to one another would have to be reduced consistently, which, however, because of the associated higher number of individual pipes would negatively impact the economy of such a heat accumulator.

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