Magnetocaloric thermal generator and method of cooling same
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Solution Overview
Problem
Magnetocaloric thermal generators face efficiency degradation due to significant heating or cooling of the cold or hot sides when exchanging thermal energy with external applications having large temperature differences, leading to a degradation of the thermal gradient and reduced usable output.
Innovation Solution
The magnetocaloric thermal generator incorporates a bypass pipe system that allows the primary fluid to flow unidirectionally from an outlet point to an injection point, optimizing heat exchange between the primary and secondary circuits by minimizing the impact on the thermal gradient, with adjustable flow rates and various heat exchange configurations, including counter-current, co-current, and cross-current displacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If heat exchange is performed with external applications having large temperature differences, then thermal energy transfer is achieved, but the thermal gradient is degraded and thermal efficiency is reduced
Solution Approach 1:
The primary circuit is divided into two separate loops: a first loop dedicated to maintaining the thermal gradient between hot and cold sides, and a second loop for heat exchange with external applications. This segmentation allows each loop to perform its specific function independently, preventing the degradation of the thermal gradient while still enabling thermal energy transfer to external applications.
Solution Approach 2:
A thermal coupling device acts as an intermediary between the magnetocaloric elements and the external applications. This mediator enables heat exchange with external applications while isolating the primary thermal gradient maintenance loop from direct thermal interference, thus preserving the thermal efficiency of the generator.
2Productivity
If heat exchange is performed on the cold side with applications having large temperature differences, then cooling capacity is provided, but the cold side is heated and thermal gradient is degraded
Solution Approach 1:
The circuit is segmented into a first loop for thermal gradient maintenance and a second loop for cold side heat exchange. The second loop can provide cooling capacity to external applications without directly heating the cold side of the magnetocaloric elements, as the thermal coupling device mediates the heat transfer and isolates the gradient maintenance loop.
3Productivity
If heat exchange is performed on the hot side with applications having large temperature differences, then heating capacity is provided, but the hot side is cooled and thermal gradient is degraded
Solution Approach 1:
The primary circuit is divided into a first loop for maintaining the thermal gradient and a second loop for hot side heat exchange. This allows the second loop to provide heating capacity to external applications while the first loop continues to maintain the thermal gradient independently, preventing the hot side from being cooled by the heat exchange process.
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 configuration enhances the thermal energy transfer efficiency, optimizing the use of thermal output without degrading the thermal gradient, allowing for effective cooling or heating of external applications while maintaining high thermal efficiency.
Implementation Method 1
Magnetic refrigeration technology at ambient temperature has been known for more than thirty years... These thermal generators use the magnetocaloric effect (MCE) of certain materials, which consists in a variation of their temperature when they are subjected to a variable magnetic field.
Implementation Method 2
the circulation of the primary fluid is alternated and this primary fluid circulates in channels or pores passing through the magnetocaloric material... During these phases, the primary fluid flows through the magnetocaloric material and will either heat up at the contact of the material during a so-called magnetization phase, or cool down at the contact of the material during a so-called demagnetization phase.
Implementation Method 3
a heat exchange is performed with a heat transfer fluid called primary fluid in order to collect the thermal energy produced by said materials
Data Source
AI summary
A magnetocaloric thermal generator having a primary circuit fluidically connecting first and second stages of magnetocaloric elements using a heat transfer primary fluid flowing alternately back and forth. The stages being subjected to variable magnetic field of a magnetic system. The primary system includes a cold side and a hot side to which the magnetocaloric elements of the stages are fluidically connected. At least the cold side of the primary circuit has an outlet point connected to another point of the primary circuit, referred to as the injection point, on the hot side by a bypass pipe allowing the primary fluid to be displaced only from the outlet point towards the injection point. The magnetocaloric thermal generator is used in a method for cooling the secondary fluid.