Geothermal Screw Post Heat Exchanger for Drill-Free Retrofit Installation
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Solution Overview
Problem
Existing geothermal energy storage systems are expensive, require deep drilling, and are unsuitable for retrofitting existing buildings due to space and thermal radiation issues.
Innovation Solution
A geothermal heat exchanger arrangement featuring a hollow-cylindrical base body with helical thread elements that can be screwed into the ground without pre-drilling, combined with a coaxial feed pipe and insulating layer to enhance heat exchange and reduce installation costs, allowing for efficient thermal energy storage and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single heat probe is placed in the ground through deep drilling, then thermal energy storage is achieved, but installation cost and complexity increase significantly
Solution Approach 1:
The heat exchanger is divided into multiple screw posts that can be independently installed in the ground. Each screw post functions as an independent heat exchange element, allowing distributed installation without requiring a single deep borehole. This segmentation reduces installation complexity while maintaining thermal energy storage capability.
Solution Approach 2:
Instead of drilling down to install a heat probe (vertical insertion), the invention uses screw posts that are screwed into the ground from the surface (rotational insertion). This inverts the installation method from deep vertical drilling to shallow rotational screwing, significantly reducing installation complexity and cost.
2Reliability
If a well-insulated boiler is placed in the middle of a building, then thermal energy is stored, but space requirements and thermal radiation increase
Solution Approach 1:
The heat exchanger is moved from a horizontal plane (boiler room inside the building) to a vertical dimension (screw posts installed in the ground beneath the building). This dimensional change eliminates the need for significant indoor space while maintaining thermal energy storage capability. The ground-borne screw posts utilize the subsurface volume rather than building floor space.
3Reliability
If a well-insulated boiler is placed in the middle of a building, then thermal energy is stored, but thermal radiation becomes very high in summer
Solution Approach 1:
The heat storage function is extracted from the building interior (boiler room) and relocated to the ground beneath the building (screw posts). This extraction removes the source of thermal radiation from the building environment, eliminating the harmful thermal radiation effect while preserving the thermal energy storage capability in the ground.
4Adaptability or versatility
If existing buildings are retrofitted with geothermal systems, then thermal energy storage is enabled, but installation cost and complexity increase
Solution Approach 1:
The installation method is inverted from complex deep drilling to simple screwing operations. Screw posts can be easily installed in existing buildings by screwing them into the ground through the foundation or yard, eliminating the need for complex drilling equipment and procedures. This inversion makes retrofitting existing buildings practical and cost-effective.
Solution Approach 2:
The screw posts are designed to be self-installing through simple screwing operations without requiring complex drilling equipment or specialized installation procedures. The spiral threads automatically guide installation and provide anchoring, making the system suitable for retrofitting existing buildings with minimal installation complexity.
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
Enables cost-effective and easy installation of geothermal systems in existing buildings by minimizing space requirements and thermal radiation, while promoting efficient heat transfer and anchoring functionality, allowing for effective thermal energy storage and retrieval.
Implementation Method 1
The at least one threaded element displaces and compacts the soil together with the base body. This not only creates the feed for the insertion but also a good contact between the soil and the threaded element as well as the base body.
Implementation Method 2
a coaxially arranged between the base body and the flow pipe, continuous insulating layer with an axial bore with an inner diameter, wherein the inner diameter of the insulating layer substantially corresponds to the outer diameter of the flow pipe
Implementation Method 3
The at least one helical threaded element is preferably connected to the cylindrical base body in a materially bonded manner, so that an optimal heat exchange between the base body and the threaded element is possible.
Implementation Method 4
Small channels with a small hydraulic diameter are formed by the fins, so that a laminar flow with a high heat transfer coefficient can be achieved. The heat exchange is promoted and the propulsion of the heating medium can be carried out with a low pump capacity.
Data Source
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AI summary
The invention relates to a heat exchanger screw post (1) comprising: a hollow cylindrical base body (2) with a cavity (3) and a closed end, wherein the base body (2) is provided on its outer side (4) with at least one helical threaded element (5); a supply pipe (6) arranged coaxially to the base body (2) and in the cavity (3) of the base body (2) with an outer diameter which extends substantially over the entire axial length of the base body (2); and a continuous insulating layer (7) arranged coaxially between the base body (2) and the supply pipe (6) with an axial bore (8) having an inner diameter, wherein the inner diameter of the insulating layer (7) corresponds substantially to the outer diameter of the supply pipe (6) and the insulating layer (7) extends substantially over the entire axial length of the base body (2);wherein an annular gap (10) is formed between the base body (2) and an outer circumferential surface (9) of the insulating layer (2), which is preferably divided into a plurality of channels (12) by a plurality of axially extending ribs (11).