System for exchanging energy with a ground

Abstract

A system for exchanging energy with a ground is disclosed. In at least one embodiment, it includes an elongate ground bore, a flexible sealing device for separating sections of the bore and extending inside and generally all along the bore and being closed at its ends, wherein the flexible sealing device, in use, is filled with a liquid whereby the flexible sealing device is pressed against walls of the bore. The system further includes at least a first duct, and heat recovery device, wherein said the at least a first duct is operatively connected to the heat recovery device and extends into the flexible sealing device. At least one sealing device is provided at the flexible sealing device at a predefined level along the bore, which at least one sealing device is adapted to seal at the level between the flexible sealing device and the bore.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a system for exchanging energy with a ground. It comprises an elongate ground bore, a flexible sealing device for separating sections of said bore and extending inside and generally all along said bore and being closed at its ends, wherein said sealing device in use is filled with a liquid whereby said sealing device is pressed against walls of said bore. The system further comprises at least a first duct, and heat recovery means, wherein said first duct extend from said heat recovery means into said sealing device.BACKGROUND ART[0002]Such systems for extracting energy from a ground are known. They are used to separate different levels in a borehole in the ground, i.a. in rocky grounds. Different layers at different levels in the ground often have a inferior quality and may comprise not only different types of rock, but also layers of sand or gravel of different fractions which reduces the strength of the walls of the bore...

AI Technical Summary

Benefits of technology

[0005]The object of the present invention is to further improve the sealing of the energy well and to preferably also reduce the costs for the complete installed energy well as well as preferably also reduce the environmental load of the completed installation.

[0006]This object is achieved by a system for exchanging energy with a ground, comprising an elongate ground bore, a flexible sealing device for separating sections of said bore and extending inside and generally all along said bore and being closed at its ends. The sealing device is in use filled with a liquid whereby said sealing device is pressed against walls of said bore. The system further comprises at least a first duct and heat recovery means. The first duct is operatively connected to said heat recovery means and extending into said sealing device. Sealing means are provided at said flexible sealing device at a predefined level along said bore, which sealing means are adapted to seal at said level between said sealing device and said bore. Since the borehole is completely sealed off from the surrounding ground there will be no leakage and the liquid used for extracting the heat energy from the ground comes in much better contact with the surrounding ground since the surface area towards the walls of the borehole is larger than the surface area of the duct against the ground water of the traditional open borehole. The flexible sealing device is in itself advantageous to transport and install into the bore since it may be laid flat and rolled onto a storage and transportation device and also be installed in a generally flat condition and not until after installation filled with liquid. Its inherent flexibility also easily adjusts to the walls of the bore and the often non-straight extension thereof. The sealing means are provided to seal off vertical levels within the bore from one another in order to minimize and preferably fully remove the leakage between different levels which otherwise may contaminate these or other levels.

[0007]In an embodiment said sealing means comprise a collar which is arranged within said flexible sealing device at said predefined level, which collar is arranged and configured to exert a radial force against said bore. Such a collar is improving the sealing off of different levels along the bore, on the outside of the sealing device, which the internal pressure within the sealing device may not always be able to. This may be needed when the bore is rather uneven or there are levels along the bore of more water permeable material.

Problems solved by technology

Such a collar is improving the sealing off of different levels along the bore, on the outside of the sealing device, which the internal pressure within the sealing device may not always be able to.

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