Magnetic heat pump design
Abstract
Heat pumps utilizing the magnetocaloric effect offer a potentially attractive alternative to conventional heat pumps and refrigerators. Many physical configurations of magnetic heat pumps are possible. Major classes include those requiring electrical energy input and those with mechanical energy input. Mechanical energy is used to move magnets, working material, or magnetic shielding. Each type of mechanical magnetic heat pump can be built in a rotary (recuperative) or reciprocal (regenerative) configuration. Machines with electrical energy input utilize modulation of the magnetic field to cause working material to execute the desired thermodynamic cycle, and can also be recuperative or regenerative. Recuperative rotary heat pumps in which working material is moved past stationary magnets is the preferred configuration. Regenerative devices suffer performance degradation from temperature change of regenerator material and mixing and conduction in the regenerator. Field modulated cycles are not practical due to ac losses in superconducting magnets. Development of methods for recuperator fluid pumping is the major challenge in design of rotary recuperative devices. Several pumping options are presented, and the design of a bench scale heat pump described.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- March 1988
- Bibcode:
- 1988STIN...8826605K
- Keywords:
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- Heat Pumps;
- Heat Transfer;
- Magnetic Fields;
- Stirling Cycle;
- Magnets;
- Regeneration (Engineering);
- Temperature Effects;
- Fluid Mechanics and Heat Transfer