Nested Thin-Walled Refrigerant Heat Exchanger
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing refrigerant-to-water heat exchangers with corrugated copper tubes require a minimum wall thickness of 0.060-0.080 inches, which is thicker than desired for efficient heat transfer, necessitating a heat exchanger with thinner walls while maintaining effective heat transfer capabilities.
Innovation Solution
A refrigerant-to-water heat exchanger design featuring inner and outer conduits with tubular members having a maximum wall thickness of 0.015 inches or less, where the inner surfaces of these conduits include enhancements such as depressions to increase surface area and facilitate heat transfer, allowing for a coaxial arrangement with expanded contact surfaces for efficient heat exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If corrugated copper tubes with thicker walls (0.060-0.080 inch) are used in traditional heat exchangers, then structural strength and reliability are improved, but heat transfer efficiency deteriorates due to increased thermal resistance
Solution Approach 1:
The patent applies thin-walled tubular members (0.010-0.020 inch wall thickness) instead of traditional thick-walled corrugated copper tubes. The thin-walled design reduces thermal resistance and improves heat transfer efficiency while maintaining structural integrity through the expanded surface area and optimized geometry of the nested tubular configuration.
Solution Approach 2:
The patent transitions from a single-walled or simple double-walled structure to a nested multi-tubular configuration where multiple tubular members are arranged concentrically. This dimensional arrangement expands the heat transfer surface area across multiple radial layers, enabling efficient heat transfer with thinner individual walls.
2Use of energy by moving object
If thinner wall thickness (0.010-0.020 inch) is used in heat exchanger tubes, then heat transfer efficiency is improved, but structural strength and durability worsen
Solution Approach 1:
The patent employs a composite structure consisting of multiple tubular members made from different materials (copper, aluminum, or other suitable materials) arranged in a nested configuration. This composite arrangement distributes mechanical stresses across multiple layers and material types, compensating for the reduced wall thickness of individual tubes while maintaining overall structural strength.
Solution Approach 2:
The heat exchanger is segmented into multiple discrete tubular members (first tubular member, second tubular member, etc.) that can be independently optimized for thickness and material properties. Each tubular member can have different wall thicknesses and materials selected to optimize both heat transfer and structural requirements for its specific functional role in the assembly.
3Ease of manufacture
If traditional double-walled corrugated copper heat exchangers are used, then manufacturing simplicity is maintained, but material usage and weight increase
Solution Approach 1:
The patent replaces traditional thick-walled corrugated copper construction with thin-walled tubular members (0.010-0.020 inch wall thickness), dramatically reducing copper material consumption. The thin-walled design is compensated by the nested multi-tubular configuration, achieving material reduction while maintaining or improving heat transfer performance.
Solution Approach 2:
The patent implements a nested configuration where multiple tubular members are arranged concentrically within each other (first tubular member within outer conduit, second tubular member within first tubular member, etc.). This nesting arrangement maximizes heat transfer surface area within a compact volume and reduces the total material required compared to traditional parallel-tube designs.
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 thinner wall design reduces material usage while maintaining or enhancing heat transfer efficiency between refrigerant and water, allowing for effective heat distribution with less material than traditional double-walled corrugated copper heat exchangers.
Implementation Method 1
Heat exchange takes place as water flows through the center of the corrugated copper tube and a refrigerant flows between the corrugated copper and steel tubes
Implementation Method 2
As hot refrigerant flows through the inner conduit and water flows between the outer conduit and the inner conduit, heat transfers from the inner conduit into the water to be distributed
Data Source
AI summary
A heat exchanger having at least one inner conduit comprising of a second tubular member coaxially disposed within a first tubular member, wherein the second tubular member outer surface is in contact with the first tubular member inner surface. Each of the first and second tubular members is composed of a material with an approximately 0.015 inch maximum wall thickness.