Closed-Loop Geothermal Boreholes With Lateral Heat-Conductive Appendages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Open loop geothermal well systems face issues with corrosion, high maintenance costs, and environmental concerns due to the extraction and disposal of groundwater, whereas closed loop systems offer advantages but require innovative enhancements for improved heat harvesting.
Innovation Solution
A geothermal heat extraction system utilizing closed loop vertical borehole heat exchangers with multiple directionally drilled appendages filled with heat conductive material, connected to a heat exchanger and an upstream working fluid manifold, which conveys hot fluid to a heat engine for mechanical energy conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If open loop geothermal systems extract groundwater for heat extraction, then heat harvesting capability is achieved, but corrosion and maintenance costs increase
Solution Approach 1:
The patent introduces a closed loop system with a working fluid as an intermediary between the geothermal heat source and the heat pump. This mediator prevents direct contact between groundwater and system components, eliminating corrosion while maintaining heat transfer efficiency. The working fluid circulates through sealed piping, transferring thermal energy without mixing with external water sources.
Solution Approach 2:
The closed loop system creates an inert, controlled environment where the working fluid circulates in isolation from corrosive groundwater. This sealed environment protects metal components from oxidation and corrosion, significantly reducing maintenance requirements while preserving the heat extraction function.
2Use of energy by moving object
If open loop systems dispose of extracted water at surface or re-inject it, then heat extraction function is maintained, but environmental concerns arise
Solution Approach 1:
The working fluid serves as an intermediary that transfers heat without requiring water extraction or disposal. This eliminates environmental concerns associated with groundwater depletion, aquifer contamination, and water resource management while maintaining effective heat extraction from the geothermal source.
Solution Approach 2:
The closed loop system is self-contained and self-sustaining, circulating the same working fluid continuously without requiring external water sources or disposal infrastructure. The system extracts heat from the ground and returns the cooled fluid to the earth, creating a sustainable cycle with no environmental waste or contamination.
3Object-generated harmful factors
If closed loop systems use vertical borehole heat exchangers, then environmental impact is reduced, but heat harvesting capability is limited
Solution Approach 1:
The patent divides the single borehole into multiple functional segments: a central vertical borehole containing the heat exchanger and multiple lateral appendages extending in different directions. This segmentation increases the total heat exchange surface area within a confined footprint, significantly enhancing heat harvesting capability while maintaining the environmental benefits of a closed loop system.
Solution Approach 2:
The system transitions from a purely vertical heat exchange configuration to a three-dimensional structure with lateral appendages extending in multiple directions. This dimensional expansion increases the contact area with the surrounding geothermal reservoir, improving heat transfer efficiency without requiring additional surface space or deeper drilling.
4Use of energy by moving object
If multiple borehole wells are used to enhance heat harvesting, then heat extraction capacity increases, but system complexity and infrastructure requirements increase
Solution Approach 1:
The patent combines multiple heat extraction functions into a single integrated borehole structure. The central borehole with its lateral appendages acts as a unified heat exchange system that performs the work of multiple separate wells, reducing infrastructure complexity while maintaining enhanced heat extraction capacity. The manifold system integrates fluid distribution to multiple appendages within one borehole, simplifying overall system architecture.
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 system significantly enhances heat harvesting capabilities, reduces maintenance and environmental impact, and provides a reliable, efficient, and environmentally friendly method for geothermal energy conversion to mechanical work.
Implementation Method 1
each well having plurality of appendages drilled in multiple directions in relation to the central borehole of the well and filled with heat conductive material in order to conduct heat from the appendages to the heat exchanger
Implementation Method 2
at least one heat engine for receiving the hot working fluid pumped from the closed loop system piping of more than one of the geothermal heat extraction wells and for performing a conversion of the hot working fluid to mechanical energy
Data Source
AI summary
A system and method of operation are shown where the system includes a plurality of geothermal wells, each well having a heat exchanger therein including closed cycle system piping to and from the surface, each well having plurality of appendages drilled in multiple directions in relation to the central borehole of the well and filled with heat conductive material in order to conduct heat from the appendages to the heat exchanger. At least one upstream working fluid manifold is connected at manifold inlets to piping conveying hot working fluid pumped from the closed cycle system piping of more than one of the plurality of geothermal heat extraction borehole wells and connected by manifold outlets to piping conveying the pumped hot working fluid to at least one heat engine.