Caloric systems

We research caloric technologies for efficient and climate-friendly cooling systems that do not require harmful refrigerants. In future, caloric heat pumps could be an alternative to compressor technology. A novel, patented system concept for heat transfer makes it possible to construct highly energy- and cost-efficient caloric heat pumps.

Heat pumps play a crucial role in energy transition. The heat pumps currently available on the market almost exclusively use compressor technology. They require refrigerants for their operation, but these are often harmful to health and/or environment, and they are relatively inefficient. Fraunhofer IPM develops efficient caloric heat pumps and cooling systems as an alternative to compressor technology. The central innovation is our novel concept for heat transfer that promises high energy and cost efficiency. In the development of caloric systems, we rely on the following caloric technologies:

Magnetocalorics

Magnetocaloric materials are magnetisable materials that heat up in a magnetic field and cool down again once the field is removed. This method is distinguished in particular by the high efficiency of the material.

Electrocalorics

The principle is the same as it is for magnetocalorics: By applying a field, heat is reversibly generated in the electrocaloric material. Unlike magnetocalorics, electrocalorics involves the use of an electric field.

Elastocalorics

Elastocaloric materials are known as »shape memory alloys« in other applications. The introduction of heat can lead to a change in shape with these alloys. The inverse effect can also be used: reversible heat can be generated by applying force to the material. A cooling system can be created using appropriate system integration in a completely analogous way to magnetocalorics or electrocalorics.

 

Magnetocaloric systems

Magnetocaloric materials are magnetizable materials that heat up in a magnetic field and cool down again once the field is removed. When used in caloric systems, they are distinguished by a high degree of efficiency.

 

Electrocaloric systems

Electrocaloric materials heat up when an electric field is applied and cool down once the field is removed. We use this effect, based on an alternating alignment of the electric dipole moments in the field, to build a cycle based on which cooling systems and heat pumps can be constructed.

 

 

 

 

 

 

Elastocaloric systems

The specific properties of shape memory alloys can be used for cooling or heat generation. When a mechanical force acts on the material, it can exchange latent heat with the environment. Using cyclical loading and unloading, a cycle can be established that can be used as a basis to set up cooling systems and heat pumps.

 

Publications »Caloric systems«

YearAuthor/Title/SourceDocument Type
2021Bachmann, Nora; Fitger, Andreas; Maier, Lena Maria; Mahlke, Andreas; Schäfer-Welsen, Olaf; Koch, Thomas; Bartholomé, Kilian:
Long-term stable compressive elastocaloric cooling system with latent heat transfer
In: Communications Physics, Vol.4 (2021), Art. 194, 6 pp.
Journal Article
2020Maier, Lena Maria; Corhan, Patrick; Barcza, Alexander; Vieyra, Hugo; Vogel, Christian; König, Jan D.; Schäfer-Welsen, Olaf; Wöllenstein, Jürgen; Bartholomé, Kilian:
Active magnetocaloric heat pipes provide enhanced specific power of caloric refrigeration
In: Communications Physics, Vol.3 (2020), Art. 186, 6 pp.
Journal Article
2020Maier, Lena Maria; Hess, Tobias; Kaube, Alexandra; Corhan, Patrick; Fitger, Andreas; Bachmann, Nora; Schäfer-Welsen, Olaf; Wöllenstein, Jürgen; Bartholomé, Kilian:
Method to characterize a thermal diode in saturated steam atmosphere
In: Review of scientific instruments, Vol.91 (2020), 6, Art. 065104, 14 pp.
Journal Article
2020Hess, Tobias; Vogel, Christian; Maier, Lena Maria; Barcza, Alexander; Vieyra, Hugo; Schäfer-Welsen, Olaf; Wöllenstein, Jürgen; Bartholomé, Kilian:
Phenomenological model for a first-order magnetocaloric material
In: International journal of refrigeration, Vol.109 (2020), pp.128-134
Journal Article
2020Hess, Tobias; Maier, Lena Maria; Bachmann, Nora; Corhan, Patrick; Schäfer-Welsen, Olaf; Wöllenstein, Jürgen; Bartholomé, Kilian:
Thermal hysteresis and its impact on the efficiency of first-order caloric materials
In: Journal of applied physics, Vol.127 (2020), No.7, Art. 075103, 28 pp.
Journal Article
2019Hess, Tobias; Maier, Lena Maria; Corhan, Patrick; Schäfer-Welsen, Olaf; Wöllenstein, Jürgen; Bartholomé, Kilian:
Modelling cascaded caloric refrigeration systems that are based on thermal diodes or switches
In: International journal of refrigeration, Vol.103 (2019), pp.215-222
Journal Article
2018Maier, Lena Maria; Hess, Tobias; Schäfer-Welsen, O.; Wöllenstein, Jürgen; Bartholomé, Kilian:
Towards high cycle frequencies for magnetocaloric cooling systems - a proof of principle: Abstract
(International Conference on Caloric Cooling - Thermag <8, 2018, Darmstadt>)
In: TU Darmstadt: Thermag VIII, International Conference on Caloric Cooling 2018. Abstract Book: Darmstadt, Germany, September 16-20, 2018. Darmstadt, 2018, 1 pp.
Conference Paper
2017Bartholomé, Kilian; Hess, Tobias; Winkler, Markus; Mahlke, Andreas; König, Jan D.:
New concept for high-efficient cooling systems based on solid-state caloric materials as refrigerant
(Conference on Energy and Thermal Management, Air Conditioning and Waste Heat Recovery <1, 2016, Berlin>)
In: Junior, Christine (Ed.): Energy and Thermal Management, Air Conditioning, Waste Heat Recovery: 1st ETA Conference, December 1-2, 2016, Berlin, Germany. Cham: Springer International Publishing, 2017, pp. 178-186
Conference Paper
This publication list has been generated from the publication database Fraunhofer-Publica.