Coaxial geothermal probe and method for making a coaxial geothermal probe
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Solution Overview
Problem
The high production costs of traditional coaxial geothermal probes, primarily due to the need for deep drilling, make them economically unviable, especially for buildings with low energy consumption.
Innovation Solution
A coaxial geothermal probe design featuring a metal outer pipe with a head element and additional elements that use a hydraulic actuator to drive into the ground, reducing the need for deep drilling by applying axial thrust and rotating to minimize friction, allowing for shorter, less expensive probe installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional drilling methods are used to install geothermal probes, then the probes can be installed in the ground, but the production costs become excessively high due to the need for deep boreholes (100-200 meters)
Solution Approach 1:
The geothermal probe is divided into multiple modular sections that can be connected in series. Each section has standardized connection interfaces, allowing the probe to be assembled from shorter segments rather than requiring a single deep borehole. This segmentation enables installation in shallower ground while achieving the same total heat exchange length, significantly reducing drilling costs.
Solution Approach 2:
The probe system incorporates adjustable and configurable components that allow adaptation to different installation depths and ground conditions. The modular design enables dynamic adjustment of probe length and configuration based on specific site requirements, optimizing the balance between installation cost and heat exchange efficiency.
2Reliability
If deep boreholes (100-200 meters) are created for probe installation, then adequate heat exchange capacity is achieved, but the installation becomes economically unviable for low energy consumption buildings
Solution Approach 1:
The probe is segmented into modular sections that can be connected to achieve the required total length for adequate heat exchange capacity. This allows installation in shallower ground with multiple shorter sections rather than one deep borehole, reducing installation costs while maintaining the necessary heat exchange surface area and capacity.
Solution Approach 2:
The coaxial design nests the inner pipe within the outer pipe, creating an annular heat exchange chamber. This nested structure maximizes the heat exchange surface area within a compact radial footprint, allowing adequate heat exchange capacity to be achieved with shorter probe lengths, thereby reducing installation costs.
3Ease of operation
If the inner pipe lower end is positioned at a distance from the outer pipe lower end, then fluid communication with the annular chamber is enabled, but the probe requires complex installation procedures
Solution Approach 1:
The probe is divided into modular sections with standardized connection interfaces. Each segment includes integrated sealing and connection components that simplify assembly. The segmentation allows the complex coaxial structure to be assembled from simpler, pre-fabricated modules, reducing overall installation complexity while maintaining fluid flow functionality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly lowers production costs by eliminating the need for extensive drilling and enables the use of geothermal probes in various ground types, including those with rocky inclusions, by using shorter, more affordable probes.
Implementation Method 1
driving the head element (13) into the ground (11) by applying an axial thrust to it
Implementation Method 2
rotating to minimize friction
Implementation Method 3
exchanging heat with the ground
Data Source
Figure 1~4
Figure 5~6
Figure 7~8
AI summary
A method for making coaxial geothermal probes that comprise a hollow outer pipe (2) and an inner pipe (5), wherein inserting the outer pipe (2) in the ground comprises: - driving into the ground using pressure, applying an axial thrust to it that is generated by means of a hydraulic actuator (30), a head element (13) that is tubular and closed at the bottom by a driving head (18) and equipped with a first thread (19) at the top; screwing a second thread (24) of an additional tubular element (14) to the first thread (19) of the head element (13), creating a fluidtight connection between the head element (13) and the additional element (14); further driving into the ground (11) using pressure the assembly constituted of the head element (13) and of the additional element (14), applying an axial thrust to them that is generated by means of a hydraulic actuator (30); and optionally performing once or more the steps of screwing the second thread (24) of a further additional element (14) to a free first thread (19) of an additional element (14) already driven into the ground (11) and connected to the head element (13), and further driving the whole assembly into the ground (11) using pressure.