Staged Magnetocaloric Heat Pump for Broad Temperature Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional heat pump systems using fluid refrigerants face inefficiencies, environmental concerns, and operational limitations across varying ambient temperatures, making them impractical for widespread use, especially in applications like refrigerator appliances.
Innovation Solution
A heat pump system utilizing magnetocaloric materials (MCMs) with a regenerator housing and magnet assembly that creates a magnetic field, allowing for staged operation of MCMs within and outside the magnetic field to efficiently exchange heat, coupled with a circulating working fluid system for effective temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional fluid refrigerant heat pump systems are used, then the systems can operate with simple compression and expansion mechanisms, but the systems achieve only about 45 percent or less of the maximum theoretical Carnot cycle efficiency
Solution Approach 1:
The patent replaces the conventional mechanical compression and expansion system with a magnetocaloric system that uses magnetic field application and removal to achieve heating and cooling. The magnetocaloric material undergoes magnetic field-induced temperature changes, eliminating the need for mechanical compressors and expansion valves, thereby reducing mechanical complexity while potentially improving thermodynamic efficiency
Solution Approach 2:
The patent utilizes the magnetic field-induced phase transition or magnetic ordering transition in magnetocaloric materials to achieve temperature changes. When a magnetic field is applied to the MCM, the magnetic moments become more ordered and the material generates heat; when the field is removed, the moments become disordered and the material absorbs heat, enabling efficient heat transfer without mechanical work
2Loss of energy
If magnetocaloric materials are used in heat pump systems, then higher theoretical Carnot cycle efficiency can be achieved, but relatively large and expensive magnets are required
Solution Approach 1:
The patent divides the magnetocaloric system into multiple discrete stages, each containing MCM and associated magnetic components. This segmentation allows for modular construction, enabling the use of smaller, more cost-effective magnets in each stage rather than requiring one large expensive magnet system, while maintaining overall high efficiency through the staged approach
Solution Approach 2:
The patent integrates the magnetocaloric material directly with the heat transfer fluid pathway, merging the magnetic field generation and heat exchange functions into a unified system. This integration eliminates the need for separate mechanical compression and heat transfer components, reducing overall system cost while achieving high Carnot efficiency
3Loss of energy
If magnetocaloric materials are used in heat pump systems, then higher theoretical Carnot cycle efficiency can be achieved, but the systems may not operate with enough efficiency to justify capital cost
Solution Approach 1:
The patent employs a staged configuration where multiple MCM stages operate in sequence through the magnetic field application cycle. As one stage is being heated by magnetic field application, another stage is simultaneously cooling by field removal, ensuring continuous heat transfer and maintaining high operational efficiency throughout the cycle, thereby justifying the capital investment through sustained productive performance
4Adaptability or versatility
If magnetocaloric materials are used in heat pump systems, then operational flexibility across broader temperature ranges can be achieved, but the MCMs are capable of accepting and generating heat only within a much narrower temperature range than presented by ambient conditions
Solution Approach 1:
The patent divides the thermal management system into multiple stages, with each stage containing MCM optimized for a specific temperature range. This segmentation allows different MCM materials with different Curie temperatures to be deployed in different stages, collectively covering a broad ambient temperature range from below freezing to over 90°F, while each individual stage operates within its optimal narrow temperature window
Solution Approach 2:
The patent applies different magnetocaloric materials with locally optimized properties to different stages of the system. Each stage uses MCM specifically selected for its magnetic transition temperature characteristics, enabling the system to adapt to varying ambient conditions by activating appropriate stages, thereby achieving broad overall temperature flexibility through locally optimized components
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 achieves higher theoretical Carnot cycle efficiency and operational flexibility across a broader temperature range, addressing the limitations of traditional heat pump systems while being cost-effective and suitable for various applications.
Implementation Method 1
Magnetocaloric materials (MCMs)—i.e. materials that exhibit the magnetocaloric effect—provide a potential alternative to fluid refrigerants for heat pump applications. In general, the magnetic moments of an MCM will become more ordered under an increasing, externally applied magnetic field and cause the MCM to generate heat. Conversely, decreasing the externally applied magnetic field will allow the magnetic moments of the MCM to become more disordered and allow the MCM to absorb heat.
Implementation Method 2
a magnet assembly, the magnet assembly creating a magnetic field
Implementation Method 3
a heat pump system that can effectively use an MCM would be useful... a heat pump system utilizing magnetocaloric materials (MCMs) with a regenerator housing and magnet assembly that creates a magnetic field, allowing for staged operation of MCMs within and outside the magnetic field to efficiently exchange heat, coupled with a circulating working fluid system for effective temperature regulation
Data Source
AI summary
A heat pump includes a magnet assembly which creates a magnetic field, and a regenerator housing which includes a body defining a plurality of chambers, each of the plurality of chambers extending along a transverse direction orthogonal to the vertical direction. The heat pump further includes a plurality of stages, each of the plurality of stages including a magnetocaloric material disposed within one of the plurality of chambers and extending along the transverse direction between a first end and a second end.