Uncategorized - Laboratory for refrigeration and district energy

New article: Roadmap for electrocaloric films characterization

admin — Thu, 28 May 2026 08:06:32 +0000

The article Roadmap for electrocaloric films characterization, published in iScience (Cell Press), presents a numerical investigation of substrate and infrared (IR) coating effects on the characterization of electrocaloric thick-film structures for future cooling applications.

Researchers from the Laboratory for Refrigeration and District Energy at the Faculty of Mechanical Engineering, University of Ljubljana, in collaboration with the Jožef Stefan Institute, investigated how substrate thermal properties and high-emissivity black coating thickness influence the accuracy of infrared temperature measurements of electrocaloric materials. The aim of the study was to establish guidelines for optimized characterization of electrocaloric structures at the micro- and nano-scale.

Using numerical simulations, the researchers demonstrated that substrates with low thermal effusivity and low thermal conductivity significantly reduce heat losses during measurements, enabling more accurate determination of the electrocaloric response. In addition, the influence of electrocaloric film thickness and black coating thickness on the IR correction factor was systematically analyzed. The results show that low single-digit correction factors can be achieved when the electrocaloric layer is thicker than the coating.

The study provides important guidelines for reliable electrocaloric material characterization and offers a roadmap for the design of future micro-scale caloric cooling systems..

Link: https://www.cell.com/iscience/fulltext/S2589-0042(26)01340-4

The post New article: Roadmap for electrocaloric films characterization first appeared on Laboratory for refrigeration and district energy.

World Energy Day 2026

admin — Tue, 10 Feb 2026 13:41:58 +0000

On February 14, we mark World Energy Day, a moment to reflect on how deeply energy shapes our daily lives and how critical it is to use it responsibly. From lighting our homes and powering transport to enabling food production and economic growth, energy supports modern society and quality of life worldwide.

At the same time, the global energy system faces a defining challenge. Scientific consensus is clear that emissions must be reduced significantly by 2030 and reach net zero by 2050 to limit the worst impacts of climate change. While renewable sources such as wind and solar continue to grow rapidly and are becoming dominant in electricity generation, fossil fuels still account for a large share of global energy supply.

World Energy Day is therefore not just a celebration, but a call to action to improve energy efficiency, accelerate the transition to renewables, and rethink how we produce and consume energy. A sustainable energy future is not just an option: it is essential.

The post World Energy Day 2026 first appeared on Laboratory for refrigeration and district energy.

Cool BatMan featured as M-ERA.NET Success Story

admin — Tue, 10 Feb 2026 13:40:49 +0000

The Cool BatMan project has been recognized as a Success Story by M-ERA.NET.

The project aimed to build a fundamental understanding of the dynamic thermal behavior of a compact cooling concept. It combines magnetocaloric materials, exploiting the magnetocaloric effect, with electrowetting-on-dielectric (EWOD) digital microfluidics. The work included advanced microfabrication and new characterization approaches.

A key outcome is the demonstration that digital microfluidics, widely used in bioanalytical lab-on-a-chip systems, also has strong potential for thermal management at the mini- and microscale.

We thank our consortium partners: Jožef Stefan Institute, Leibniz Institute for Solid State and Materials Research Dresden, and the University of Barcelona. We also thank M-ERA.NET for the recognition.

Read the full success story here:
https://www.m-era.net/news/successtory_coolbatman

The post Cool BatMan featured as M-ERA.NET Success Story first appeared on Laboratory for refrigeration and district energy.

High-temperature electrocaloric heat pump presented at the High-temperature heat pump symposium

admin — Fri, 23 Jan 2026 09:56:23 +0000

Researchers from the Laboratory for Refrigeration and District Energy (LAHDE) have visited High-temperature heat pump symposium in Copenhagen, Danmark. The event offered an excellent overview of the latest research and industrial developments in high-temperature heat pumps, with many insightful discussions and opportunities to exchange perspectives with experts from industry and academia.

We were pleased to present our work on solid-state electrocaloric heat pump in the poster session and to receive valuable feedback that will support our ongoing research. Many thanks to the organizers for a well-structured and high-quality symposium, and to all colleagues for the engaging discussions.

The post High-temperature electrocaloric heat pump presented at the High-temperature heat pump symposium first appeared on Laboratory for refrigeration and district energy.

A completed research secondment at the Bundesanstalt für Materialforschung und -prüfung (BAM)

admin — Tue, 13 Jan 2026 11:16:20 +0000

Our PhD student Kamyar Dobakhti recently completed a research secondment at the Bundesanstalt für Materialforschung und -prüfung (BAM). This secondment provided valuable hands-on experience in X-ray tomography and Life Cycle Assessment (LCA) methodologies relevant to thermomagnetic heat exchanger development.

During his stay at BAM, Kamyar visited several X-ray tomography facilities and a mechanical testing setup, gaining in-depth insight into tomography procedures for structural characterization and defect analysis. Close collaboration with experts in the field enabled a detailed understanding of how these techniques can be applied to optimize manufacturing parameters and material design.

Furthermore, precise geometrical parameters extracted from the X-ray tomography data were directly incorporated into numerical simulations. The primary focus of the secondment was the development of a numerical model to evaluate the heat transfer characteristics of different heat exchanger geometries, supporting the optimization of thermomagnetic heat exchanger performance.

A heartfelt thank you to Dr.-Ing. Anja Waske, Heike Q. and Savvina Papaioannou from BAM for their warm welcome and support. I also want to express my gratitude to our group leaders, the Laboratory for Refrigeration and District Energy, and the entire team for providing me with this incredible opportunity.

The post A completed research secondment at the Bundesanstalt für Materialforschung und -prüfung (BAM) first appeared on Laboratory for refrigeration and district energy.

Ultra-high-temperature electrocaloric heat pump

admin — Mon, 05 Jan 2026 09:01:01 +0000

Researchers from the Laboratory for Refrigeration and District Energy (LAHDE) have published first study on high-temperature electrocaloric heat pump in Journal of Energy conversion and management, one of the world’s leading scientific journal in the field of energy.

Nearly a quarter of waste heat is generated at temperatures exceeding 300 °C, yet conventional heat pump technologies remain inefficient in recovering and utilizing heat from such high temperature sources. In this study, we introduce a novel electrocaloric heat pump designed to operate with heat sources and sinks at ultra-high temperatures. The proposed heat pump system incorporates an active electrocaloric regenerator featuring PbZr_0.52Ti_0.48O₃ (PZT) epitaxial thin-film multilayers, which exhibit a superior electrocaloric adiabatic temperature change of 11.03 K at 402 °C (675 K), and pressurized helium gas as the working fluid. We conducted a parametric analysis to simulate the performance of the ultra-high-temperature electrocaloric heat pump and identified the optimal conditions for single- and multi-stage configurations. The single-stage setup achieved a maximum heating COP of 7.8 at a 30 K temperature span across the regenerator at a heat source temperature of 660 K. In comparison, the multi-stage configuration yielded the highest heating power 113.3 W/kg_EC and a max. COP 2.7 between 630 and 690 K. This study established a foundation for notable advancements in ultra-high-temperature heat pumps by employing electrocaloric energy conversion.

Link: https://www.sciencedirect.com/science/article/pii/S019689042501338X

The post Ultra-high-temperature electrocaloric heat pump first appeared on Laboratory for refrigeration and district energy.

Emerging opportunities for high-temperature solid-state and gas-cycle heat pumps

admin — Sun, 21 Dec 2025 12:51:38 +0000

Researchers from the Laboratory for Refrigeration and District Energy (LAHDE), together with an international team, have published a study in Nature Energy (Springer Nature), the world’s leading scientific journal in the field of energy. The paper offers the first comprehensive assessment of an often-overlooked opportunity: alternative high-temperature heat-pump technologies that could replace inefficient fossil-fuel combustion and direct electric heating in industry and the energy sector. Doing so could significantly reduce energy use, greenhouse-gas emissions, and thermal pollution.

Heat lies at the core of the energy challenge. Around 50% of final energy consumption is used for heating and cooling, and roughly 50% of final energy is ultimately released as waste heat—heat that is frequently discharged into the environment via cooling towers, the warming of rivers or seawater, and other outlets. The study shows that high-temperature heat pumps can capture this waste heat and upgrade it efficiently to much higher temperature levels, suitable for demanding industrial processes.

Today’s commercial high-temperature heat pumps are typically limited to about 250 °C, whereas many industrial processes require higher temperatures—up to, or even beyond, 1000 °C. The newly published research therefore systematically presents and compares alternative approaches that could enable a step change: caloric, thermoelectric and thermoacoustic technologies, as well as mechanical processes based on Stirling and Brayton cycles.

Link: https://www.nature.com/articles/s41560-025-01908-4

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Delft days on magnetocaloric 2025

admin — Wed, 26 Nov 2025 14:30:08 +0000

On November 20 and 21, the 6th DDMC Conference took place in Delft, Netherlands, organized by the Technical University of Delft.

During the conference, our student Kamyar Dobakhti presented his poster on the Numerical simulation of a high-frequency regenerative thermomagnetic generator, which attracted significant interest from attendees.

Additionally, Professor Dr. Andrej Kitanovski delivered an invited talk titled Magnetocaloric Cooling and Heat Pump Technologies: Competitive Outlook, which was highly regarded.

The post Delft days on magnetocaloric 2025 first appeared on Laboratory for refrigeration and district energy.

Heat4Energy School “Simulations, data mining and artificial intelligence”

admin — Wed, 26 Nov 2025 14:20:29 +0000

From November 17th to 19th, the school “Simulations, data mining and artificial intelligence” took place in Delft, Netherlands, for PhD students participating in the HEAT4ENERGY project. The event was hosted by partners at the Technical University of Delft (TUD).

Over the course of this intensive two-day program, students attended lectures on:

Basics of phase field simulations
Modeling of active magnetocaloric regenerators for heat pump applications
Developing multiphysics software using finite elements
First-principles theory of magnetic materials
AI in computational Molecules and Materials research

In the practical sessions, participants engaged in hands-on exercises in finite elements, and the first-principles theory method.

In addition, students received insightful presentations on Science Communication and Commercializing magnetocaloric materials by Magneto. The program also included visits to Magneto and the Yes!Delft startup incubator.

Overall, the workshop was highly productive and sparked strong interest and engagement among all participants.

The post Heat4Energy School “Simulations, data mining and artificial intelligence” first appeared on Laboratory for refrigeration and district energy.

We visited European Cryogenics Days (ECD) 2025 and Cryogenics Workshop (CHMT) 2025

admin — Fri, 31 Oct 2025 07:12:30 +0000

Set on the green campus of the University of Twente, the European Cryogenics Days (ECD) 2025 and Cryogenics Workshop (CHMT) 2025 brought together leading experts from academia and industry to explore the latest advancements in cryogenics. The event took place from October 27 to 30, 2025. The event was hosted by Cryogenics Society of Europe and HEPTech.

We were proud to take part and present our work.
Darja Gačnik delivered a talk titled “Modeling internal temperature profiles in LN₂-cooled cryogenic terminals with temperature-dependent axial conduction and convection coupling.”
Katja Vozel presented a poster titled “Enhancing cryogenic thermal diode performance via temperature-dependent contact resistance.”

This conference offered a fantastic opportunity to deepen our knowledge in cryogenics, share our research with the community, gain fresh ideas, and build new connections and collaborations. We returned inspired and excited to continue contributing to advancing the low-temperature thermal management in the future!

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