Patent Description:
The problem with the above-described arrangement is that it is challenging to install into the loose soil layer. Previously, there is known a method wherein an open ditch is dug in the soil for placing the ground source heat pipes. Then, this open ditch is covered. On the other hand, there is known a method which is used for installing ground source heat pipes into the bedrock. This method utilises a drill to open an installation hole and, wherein, a drill head is run by means of drilling pipes connected to each other. Pressurised air is led to the opened hole which air pushes loose soil upwards and out of the installation hole. Similarly, the method utilises installation pipes or guide pipes to follow the drill head to the section of the installation hole which is located in the loose soil layer. The guide pipes prevent the open installation hole from collapsing and the opened installation hole can be kept open for the installation of the ground source heat pipes. When the installation hole has been drilled to a desired depth, the drilling pipes are pulled out of the installation hole and, then, the ground source heat pipes are led to the installation hole. There is also a known method wherein the ground source heat pipes are installed inside steel piles installed for the foundation of a building.

The problem with the installation of ground source heat pipes only to the loose soil layer is that the digging of the open ditch requires a lot of land masses to be moved when digging and covering the ditch. On the other hand, the use of a rock drill is poorly applicable to loose soil.

<CIT> discloses a method for installing ground source heat pipes.

It is thus the object of the invention to provide a novel method. The method according to the invention is characterised by what is disclosed in the independent claim. Some preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on getting an installation pipe or a combination of installation pipes deeper into the soil by means of a work machine which leads an opening head to the soil by means of the installation pipes. Ground source heat pipes are fastened with fastening means to follow the opening head, and they can be led to the soil within the same work phase as the installation hole itself is opened. The opening head is provided with a transverse pin in its upper part, which pin is in turn set in a slot open from the bottom, being at the lower end of the installation pipe. When the opening head, installation pipes and ground source heat pipes are in the desired depth, the installation pipes are lifted up, whereby the opening head and the ground source heat pipes remain in the soil.

The opening head can be a screw head which includes at least one screw blade. The work machine rotates and presses the installation pipe or the combination of installation pipes into the soil, whereby the screw head set in the installation pipe makes them sink into the soil. The ground source heat pipes are fastened to the screw head and they can be led to the installation hole in the same work phase as the installation pipe is rotated into the soil. The ground source heat pipes are set into connection with the installation pipe and they follow the rotational motion of the installation pipe. The screw head is connected to the lower end of the installation pipe by means of a pin set in the screw head which pin sets in the slot at the end of the installation pipe. When the screw head, the installation pipe and the ground source heat pipes are in the desired depth, the installation pipe is rotated or joggled in the opposite rotation direction, whereby the installation pipe comes loose from the screw head and the installation pipe can be lifted off the soil. The screw head and the ground source heat pipes remain in the soil.

The opening head can also be a cone head of conical shape with its diameter substantially larger than the diameter of the installation pipe. In this embodiment, the work machine drives the installation pipe and presses the installation pipe or the combination of installation pipes into the soil, whereby the conical head set in the installation pipe makes them sink into the soil. The ground source heat pipes are fastened to the conical head in the same work phase as the installation pipe is driven into the soil. The ground source heat pipes are set into connection with the installation pipe and they follow the installation pipe. The conical head is connected to the lower end of the installation pipe by means of a pin set in the conical head which pin sets in the slot at the end of the installation pipe. When the conical head, the installation pipe and the ground source heat pipes are in the desired depth, the installation pipe is rotated or joggled, whereby the installation pipe comes loose from the conical head and the installation pipe can be lifted up from the soil. The conical head and the ground source heat pipes remain in the soil.

An advantage of the method according to the invention is that the ground source heat pipes can be led to the installation hole in the same work phase as the making of the installation hole itself. The pin of the opening head can be provided with screw threads, with a nut set in which, the opening head can be temporarily fastened to the installation pipe in order to move the installation pipe and the opening head before setting them on the soil surface. This arrangement can help to avoid the falling of the opening head in the transfer phase.

It is also possible to lead the ground source heat pipe in the soil with two work phases. Then, the opening hole is opened as described above and the ground source heat pipes are led to the installation pipe in a different work phase. In this method, not part of the present invention, when leading the ground source heat pipes in the soil, a fastening means fastened to their U loop grabs the opening head, e.g. a pin in it, when the ground source heat pipes are led in the correct depth in the installation pipe. Then, the installation pipes can be lifted up and the opening head and the ground source heat pipes remain in the soil.

The invention is now described in closer detail in connection with some embodiments and with reference to the accompanying drawings, in which:.

With reference to <FIG>, means for moving, rotating and driving into soil an installation pipe <NUM> are connected to a work machine <NUM>. Ground source heat pipes <NUM> are set into connection with the installation pipe <NUM> such that some ground source heat pipes <NUM> are inside the installation pipe <NUM> fastened to an opening head <NUM> and some are outside the installation pipe <NUM>. The opening head <NUM> is connected to the lower end of the installation pipe <NUM>. The work machine <NUM> takes the opening head <NUM> and the installation pipe <NUM> into the soil either by rotating or driving. The surface of the installation pipe <NUM> is substantially smooth in order to be able to effortlessly lead it to the soil. Substantially, unevennesses in the installation pipe <NUM> should be smaller than <NUM>.

In an embodiment, the opening head <NUM> is provided with at least one screw blade <NUM>. This is shown in <FIG>. The work machine <NUM> rotates and presses the installation pipe <NUM> into the soil, whereby the opening head <NUM> provided with the screw blade <NUM> set in the installation pipe <NUM> can make them sink into the soil. The ground source heat pipes <NUM> are fastened to the opening head <NUM> and they can be led into the installation hole in the same work phase as the installation pipe <NUM> is rotated into the soil. The ground source heat pipes <NUM> are set into connection with the upper part of the installation pipe <NUM> and they follow the rotational motion of the installation pipe <NUM>. The opening head <NUM> is connected to the lower end of the installation pipe <NUM> by means of a pin <NUM> set in the opening head <NUM>, which pin sets in a slot <NUM> at the end of the installation pipe <NUM>. When the opening head <NUM>, the installation pipe <NUM> and the ground source heat pipes <NUM> are in the desired depth, the installation pipe <NUM> is joggled and rotated in the opposite rotation direction, whereby the installation pipe <NUM> comes loose from the opening head <NUM> and the installation pipe <NUM> can be lifted up from the soil. The opening head <NUM> and the ground source heat pipes <NUM> remain in the soil.

In an embodiment, the opening head <NUM> can be of the shape of a cone <NUM> such that its tip forms the lower part of the opening head <NUM> and the diameter of the upper part of the opening head <NUM> is substantially larger than the diameter of the installation pipe <NUM>. This is shown in <FIG>. In this embodiment, the work machine <NUM> drives the installation pipe <NUM> into the soil, whereby the opening head <NUM> set in the installation pipe <NUM> makes the installation pipe <NUM> sink into the soil. The ground source heat pipes <NUM> are fastened to the opening head <NUM> and they are led into the installation hole in the same work phase as the installation pipe <NUM> is driven into the soil. The ground source heat pipes <NUM> are set into connection with the installation pipe <NUM> and they follow the installation pipe <NUM>. The opening head <NUM> is connected to the lower end of the installation pipe <NUM> by means of a pin <NUM> set in the opening head <NUM>, which pin sets in a slot <NUM> at the end of the installation pipe <NUM>. When the opening head <NUM>, the installation pipe <NUM> and the ground source heat pipes <NUM> are in the desired depth, the installation pipe <NUM> is joggled and rotated, whereby the installation pipe <NUM> comes loose from the opening head <NUM> and the installation pipe <NUM> can be lifted up from the soil. The opening head <NUM> and the ground source heat pipes <NUM> remain in the soil.

In an embodiment, the slot <NUM> of the installation pipe <NUM> is manufactured such that the slot <NUM> widens towards the lower end of the installation pipe <NUM>. The slot <NUM> is shaped such that, seen in relation to the rotation direction of the installation pipe <NUM>, a rear edge <NUM> of the slot <NUM> is straight and a front edge <NUM> of the slot <NUM> is bevelled. This is shown in <FIG>. This ensures that, when the installation pipe <NUM> is rotated in the opposite direction, the installation pipe <NUM> comes loose from the opening head <NUM> and the installation pipe <NUM> can be lifted up from the soil such that the opening head <NUM> and the ground source heat pipes <NUM> remain in the soil.

In an embodiment, the pin <NUM> of the opening head <NUM> is provided with screw threads <NUM>, with a nut <NUM> set in which, the opening head <NUM> can be temporarily fastened to the installation pipe <NUM> in order to move the installation pipe <NUM> and the opening head <NUM> before setting them on the soil surface. This arrangement can help to avoid the falling of the opening head <NUM> in the transfer phase.

In an embodiment, it is also possible to set in the installation pipe <NUM> filling material, such as concrete or crushed stone fines, whereby the ground source heat pipes <NUM> quickly reach good thermal conductivity in connection with the installation of the ground source heat pipes <NUM>. Then, no air or air pockets remain between the walls of the installation hole and the ground source heat pipes <NUM> to impede conduction of heat from the soil to the ground source heat pipes <NUM>.

In an embodiment, not part of the present invention, the ground source heat pipes <NUM> are led into the soil in two work phases. Then, the opening hole is opened as described above and the ground source heat pipes <NUM> are led into the installation pipe <NUM> in a different work phase. In this method when leading the ground source heat pipes <NUM> in the soil, a fastening means <NUM> fastened to their U loop <NUM> grabs the opening head <NUM>, e.g. the pin <NUM> in it, when the ground source heat pipes <NUM> are led in the correct depth in the installation pipe <NUM>. After that, the installation pipes <NUM> can be lifted up and the opening head <NUM> and the ground source heat pipes <NUM> remain in the soil. In an embodiment, not part of the present invention, the fastening means <NUM> are hooks set opposite each other. When leading the ground source heat pipes down, at least one of the hooks can be made to grab the pin <NUM> of the opening head <NUM>.

Claim 1:
A method for installing ground source heat pipes (<NUM>), wherein
leading the ground source heat pipes (<NUM>) to an installation pipe (<NUM>);
fastening the ground source heat pipes (<NUM>) to an opening head (<NUM>) by means of fastening means (<NUM>) before leading the installation pipe (<NUM>) into the soil;
setting the installation pipe (<NUM>) into connection with the opening head (<NUM>), wherein a pin (<NUM>) of the opening head (<NUM>) is set into a slot (<NUM>) of the installation pipe (<NUM>);
fastening the installation pipe (<NUM>) by means of fastening means (<NUM>) to the opening head (<NUM>);
lifting the installation pipe (<NUM>) to a desired location;
detaching the fastening means (<NUM>);
leading the installation pipe (<NUM>) into the soil; and
lifting the installation pipe (<NUM>) up from the soil such that the opening head (<NUM>) remains in the soil.