Magnetocaloric Wire with Surface Geometry for Wide Temperature Span
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Solution Overview
Problem
Magnetic heat pump devices using linear magnetic bodies have a narrow temperature span compared to granular magnetic bodies, limiting their applicability, as they do not effectively achieve a wide temperature gradient in the heat exchanger.
Innovation Solution
A wire with a magnetocaloric effect is designed, featuring a non-circular cross-sectional shape and twisted configuration with concave and convex portions on its surface, enhancing fluid flow turbulence and heat transfer rates, which is bundled into a heat exchanger and integrated into a magnetic heat pump device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If linear magnetic bodies are used in the heat exchanger, then the device structure is simple, but the temperature span is narrow
Solution Approach 1:
The patent applies asymmetry by designing the wire with a non-circular cross-sectional shape featuring concave and convex portions on its outer surface. This asymmetric geometry disrupts the fluid flow pattern, creating turbulence that enhances heat transfer efficiency and expands the temperature span capability of the heat exchanger, directly resolving the contradiction between simple structure and wide temperature span.
Solution Approach 2:
The patent utilizes curvature by incorporating concave portions and convex portions on the wire's outer surface. These curved surface features modify the fluid flow characteristics, promoting turbulent flow and improving heat transfer rates, thereby achieving a wider temperature span without significantly complicating the overall device structure.
2Power
If linear magnetic bodies are used in the heat exchanger, then manufacturing is simple, but heat transfer rate is insufficient
Solution Approach 1:
The asymmetric cross-sectional design with concave and convex portions enhances heat transfer by inducing turbulent flow, while the patent addresses manufacturing complexity by specifying feasible geometric configurations that can be produced using conventional wire drawing and forming techniques.
Solution Approach 2:
The patent optimizes specific geometric parameters of the wire, including the dimensions and distribution of concave and convex portions, to achieve optimal heat transfer performance. By carefully selecting these parameters within manufacturable ranges, the patent balances enhanced heat transfer rate with practical manufacturing considerations.
3Temperature
If granular magnetic body is used, then temperature span is wide, but pressure loss increases
Solution Approach 1:
The patent segments the magnetic material into wire form with surface irregularities rather than using granular material. This segmentation approach achieves wide temperature span through enhanced heat transfer while maintaining smoother fluid passages that reduce pressure loss compared to granular configurations.
Solution Approach 2:
The curved concave and convex surface features on the wire create effective turbulence for heat transfer enhancement without the significant pressure drop associated with granular materials, as the overall wire structure maintains more streamlined fluid flow paths.
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 wire's unique geometry increases the heat transfer rate, allowing for a wider temperature span in the heat exchanger, thereby enhancing the magnetic heat pump's performance and applicability.
Implementation Method 1
a wire used in a magnetic heat pump device using a magnetocaloric effect
Implementation Method 2
since a flow of a fluid flowing on the surface of the wire becomes turbulent and a heat transfer rate between the wire and the fluid can be enhanced
Data Source
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AI summary
[Object] To provide a wire capable of obtaining a wide temperature span. [Solving Means] An outer surface 121 of a wire 12A formed of a magnetocaloric material having a magnetocaloric effect partially has at least one of a concave portion 122 and a convex portion 123, the concave portion 122 is recessed in a radial direction of the wire 12A, and the convex portion 123 protrudes in the radial direction in a longitudinal direction of the wire 12A.