Double-Pipe Ground Heat Exchanger for Low-Energy Circulation
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Solution Overview
Problem
Traditional geothermal heat exchange systems face inefficiencies in energy consumption and high construction costs due to linear heat exchanger pipes that limit contact area and time for heat exchange, leading to energy waste and increased excavation costs.
Innovation Solution
An underground heat exchange system utilizing a double-pipe heat exchanger with a wedge- or dome-shaped outer cylinder and flow rate reducing means, such as collision members, to enhance heat exchange efficiency and automate operations with a water level sensor, upstream pump, and controller for efficient circulation and emergency response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If linear heat exchanger pipes are used, then construction is simple, but contact area and heat exchange time are limited
Solution Approach 1:
The patent employs curved and coiled pipe configurations instead of linear pipes to increase the contact area between the heat transfer medium and the ground. The pipes are arranged in curved paths and coils within boreholes, allowing the heat exchange surface to expand significantly while maintaining a compact underground footprint, thereby resolving the contradiction between contact area and structural simplicity.
Solution Approach 2:
The patent transitions from two-dimensional linear pipe layouts to three-dimensional coiled and curved arrangements within vertical boreholes. By utilizing the vertical dimension and creating spiral or serpentine patterns, the system maximizes the heat exchange surface area within the available borehole volume, effectively increasing contact area without proportionally increasing construction complexity.
2Productivity
If bent pipes are used to increase contact area, then heat exchange efficiency improves, but excavation work and construction costs increase
Solution Approach 1:
The patent performs preliminary bending and coiling of the heat exchanger pipes before installation into the boreholes. By pre-configuring the pipes in their final curved or coiled shapes during manufacturing, the system eliminates the need for complex on-site bending operations and reduces excavation requirements, thereby maintaining high heat exchange efficiency while lowering construction costs.
Solution Approach 2:
The patent divides the heat exchanger system into multiple modular pipe sections that can be independently manufactured, bent, and assembled. These segmented modules are inserted into boreholes in stages, reducing the depth and complexity of single continuous excavations. The modular approach allows for standardized production and easier installation, reducing overall construction costs while maintaining efficient heat exchange performance.
3Productivity
If heat transfer medium is forced to circulate, then heat exchange continues, but energy waste occurs
Solution Approach 1:
The patent designs the heat exchange system to utilize natural convection currents driven by temperature-induced density differences in the heat transfer medium. The coiled pipe configuration enhances these natural circulation patterns, allowing the system to maintain continuous heat exchange without requiring external pumping energy, thereby eliminating energy waste while preserving heat exchange continuity.
Solution Approach 2:
The patent leverages periodic natural convection cycles within the closed-loop heat exchange system. As the heat transfer medium circulates through the coiled pipes, temperature and density variations create periodic flow patterns that continuously drive heat exchange between the ground and the medium, maintaining productivity without sustained energy input for forced circulation.
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
The system reduces energy consumption and management costs by leveraging natural circulation and vortex creation for improved heat exchange efficiency, while automating operations and simplifying construction with a double-pipe structure and integrated control systems.
Implementation Method 1
a ground heat exchanger (10) for exchanging heat with the ground through a heat transfer medium
Implementation Method 2
inducing the heat transfer medium to circulate by potential energy of the medium collector
Implementation Method 3
flow rate reducing means, such as collision members, to enhance heat exchange efficiency
Data Source
AI summary
An underground heat exchange system is provided to reduce energy consumption for circulation of a heat transfer medium and reduce construction, management, and maintenance costs. The underground heat exchange system includes: a double-pipe heat exchanger that is buried underground to convert a heat transfer medium into a usable form; a medium collector that collects the heat transfer medium that has dispersed its heat via a heat consumption area to circulate the same to the ground heat exchanger; and a plurality of circulation loops. The medium collector includes first and second reservoirs that are arranged in two tiers: upper and lower, spaced apart from each other, an upstream pump is provided in a first circulation loop between the first and second reservoirs, and the second reservoir is placed higher than the first reservoir. The ground heat exchanger may enhance heat exchange efficiency by increasing the contact area and time between the ground and the heat transfer medium.