Modular Magnetocaloric Thermal Diode for Efficient Heat Pumping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional heat pump systems using fluid refrigerants face inefficiencies, environmental concerns, and impractical temperature operation ranges, while magneto-caloric materials offer higher theoretical efficiency but require cost-effective and practical equipment solutions for widespread adoption.
Innovation Solution
A magneto-caloric thermal diode assembly with a stacked cylindrical design incorporating magnets and non-magnetic rings to create high and low magnetic field zones, allowing for efficient heat transfer using a magneto-caloric cylinder within a refrigerator appliance, enabling effective heat pumping across a wide range of temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional fluid refrigerant heat pumps are used, then the system can operate with simple structure, but the efficiency is limited to about 45% of maximum theoretical Carnot cycle efficiency
Solution Approach 1:
The patent replaces the conventional mechanical compression system with a magneto-caloric system that uses magnetic field changes to achieve refrigeration. The magneto-caloric material undergoes adiabatic magnetization and demagnetization cycles, substituting mechanical work with magnetic field control to achieve higher theoretical efficiency while maintaining practical system operation
Solution Approach 2:
The system changes the operating parameter from mechanical pressure changes to magnetic field strength changes. By controlling the magnetic field intensity applied to the magneto-caloric material, the system achieves temperature changes and heat transfer without mechanical compression, enabling operation at higher Carnot efficiencies
2Use of energy by moving object
If magneto-caloric materials are used to achieve higher theoretical efficiency, then the efficiency can exceed 45% of Carnot cycle, but the equipment requires relatively large and expensive magnets
Solution Approach 1:
The patent divides the magneto-caloric assembly into multiple discrete components including the magneto-caloric cylinder, thermal stages, and magnet assemblies. This segmentation allows for optimized material selection, simplified manufacturing of individual components, and potential modular assembly that reduces overall system cost while maintaining high efficiency performance
Solution Approach 2:
The patent implements a nested structure where the magneto-caloric cylinder is positioned within the thermal stages, which are in turn surrounded by the magnet assemblies. This nested arrangement maximizes the use of space, allows heat transfer through controlled thermal pathways, and integrates multiple functions (magnetic field generation, heat transfer, thermal isolation) into a compact configuration that reduces material requirements and cost
3Adaptability or versatility
If conventional refrigerant systems are used, then the system structure is simple, but the range of ambient temperatures over which the system can operate is impractical for certain locations
Solution Approach 1:
The patent designs the magneto-caloric heat pump system to perform multiple functions: it can operate as a refrigerator, freezer, or heat pump by controlling the direction of heat flow through the thermal stages. The same basic structure and magneto-caloric material can serve different temperature requirements by adjusting the magnetic field control parameters, providing universal applicability across different ambient temperature conditions without requiring fundamental system redesign
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 solution enhances the efficiency and cost-effectiveness of heat transfer, allowing for efficient cooling and heating applications, overcoming the limitations of traditional refrigeration technologies and environmental concerns associated with fluid refrigerants.
Implementation Method 1
Magneto-caloric materials (MCMs), i.e. materials that exhibit the magneto-caloric effect, provide a potential alternative to fluid refrigerants for heat pump applications. In general, the magnetic moments of MCMs become more ordered under an increasing, externally applied magnetic field and cause the MCMs to generate heat. Conversely, decreasing the externally applied magnetic field allows the magnetic moments of the MCMs to become more disordered and allow the MCMs to absorb heat.
Data Source
AI summary
A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder. A plurality of thermal stages is stacked along an axial direction between a cold side and a hot side. Each of the plurality of thermal stages includes a plurality of magnets and a non-magnetic ring. The plurality of magnets is distributed along a circumferential direction within the non-magnetic ring in each of the plurality of thermal stages. The plurality of magnets and the non-magnetic ring of each of the plurality of thermal stages collectively define a cylindrical slot. The magneto-caloric cylinder is positioned within the cylindrical slot. In each of the plurality of magnets in one of the plurality of thermal stages, a first, second, third and fourth magnet segments are positioned and oriented such that the first, second, third and fourth magnet segments collectively form a closed loop high-field zone across the cylindrical slot.