Helix Coil Heat Exchanger With Buffer Tank for Flue Heat Recovery
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Solution Overview
Problem
Existing tankless hot water systems with fin-and-tube heat exchangers suffer from inefficient energy recovery due to the use of a ceramic disc, which occupies valuable space, increases costs, and fails to harness maximum energy, leading to wasted heat and overheating issues.
Innovation Solution
A novel heat exchanger design featuring a helix coil with external fins, a radial direct-fired burner, and a buffer tank within the helix coil lumen, eliminating the need for a ceramic disc and incorporating a rope seal for enhanced heat transfer, along with a buffer tank that captures radiant and convective heat, and an optional Stirling engine for electricity generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a ceramic disc is used inside the helix coil lumen to shield hot flue gas, then components are protected from heat damage, but heat exchanger footprint is reduced, fabrication and installation costs increase, and maximum energy recovery is not achieved
Solution Approach 1:
The patent removes the ceramic disc from the helix coil lumen and replaces it with a buffer tank. This extraction eliminates the space occupation and cost issues of the ceramic disc while allowing direct heat recovery. The buffer tank is positioned to receive hot flue gas directly, converting the harmful heat into useful thermal energy for water heating.
Solution Approach 2:
The patent converts the harmful hot flue gas that would otherwise escape through gaps and cause energy loss into a beneficial heat source. By positioning the buffer tank to intercept the hot flue gas path, the system captures thermal energy that would be wasted, transforming a harmful thermal discharge into a useful heating resource.
2Quantity of substance
If a separate buffer tank is disposed externally from the fin-and-tube heat exchanger, then energy storage is provided, but system complexity and space requirements increase
Solution Approach 1:
The patent merges the buffer tank function with the heat exchanger structure by integrating the buffer tank inside the helix coil lumen. This combination eliminates the need for a separate external buffer tank, reducing system complexity and space requirements while maintaining energy storage capacity. The buffer tank and heat exchanger become a single integrated unit.
Solution Approach 2:
The buffer tank is nested within the helix coil structure, allowing the heat exchanger to serve dual purposes: heat transfer and energy storage. This nested configuration reduces the overall system footprint and eliminates the need for separate components, simplifying the 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 design enhances energy recovery, reduces costs and space requirements, prevents overheating, and allows for efficient heat transfer, while eliminating the need for external insulation and expansion tanks, resulting in a compact, efficient, and cost-effective tankless hot water system.
Implementation Method 1
A radial direct-fired burner is disposed within a top portion of the helix coil lumen
Implementation Method 2
hot flue gas can be more efficiently directed around coil tube
Implementation Method 3
The buffer tank is disposed within a bottom portion of the helix coil lumen... receives heat from the hot flue gas primarily and radiant heat from the burner secondarily
Implementation Method 4
heat transfer from flue gas to the water flowing inside the helix coil
Implementation Method 5
Fins are disposed externally over the entire length of the helix coil
Implementation Method 6
A rope seal is disposed between at least two helix coil loops to direct hot flue gas in a direction substantially circumferencing the outer perimeter of a helix coil tube
Implementation Method 7
a generally cylindrical buffer tank is disposed within a bottom portion of the helix coil lumen... receives heat from the hot flue gas primarily and radiant heat from the burner secondarily
Data Source
AI summary
A novel water heat exchanger with a helix coil incorporated into a stainless steel elongated variable diameter cylindrical housing. A buffer tank is incorporated within the lumen of the helix coil. In one embodiment, the heat exchanger utilizes a radial direct-firing burner and a blower-driven hot flue gas to heat water for domestic and commercial use. In one embodiment, at least a rope seal is disposed between adjacent coil loops of a portion of the helix coil for enhancing heat transfer to the helix coil. In one embodiment, solar and electric heating systems are combined with the helix coil heat exchanger and disposed within the buffer tank to provide supplemental heating. In another embodiment, the heat exchanger further comprises a Stirling engine comprised of a free piston having hot and cold ends that is disposed within the cavity taken up the buffer tank, wherein the hot end receives heat from the burner and the cold end is cooled by the incoming cold water line to form an electric power generator.