References
Dissemination and communication: TCCbuilder has been presented in scientific articles, at conferences, and relevant events.
Research papers
iScience: special issue
TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits
Workshops
TCCbuilder workshop
TCCbuilder WS: we discovered the possibilities of modeling thermal circuits
On Thursday, September 5, we held an online workshop where we learned about the functionality of the open source tool for modeling thermal control elements and thermal circuits, TCCbuilder.
Conferences
International congress of refrigeration
Oral presentation:
Caloric cooling modelling with a novel tool for simulating thermal control circuits
Scientific articles
iScience
The numerical study on performance evaluation of a thermal switch capacitor in a magnetocaloric cooling device
In the article The numerical study on performance evaluation of a thermal switch capacitor in a magnetocaloric cooling device, published in the journal iScience (IF 6.107), researchers from the Laboratory of Refrigeration and District Energy at the Faculty of Mechanical Engineering numerically analyze the performance of a thermal control element (thermal switch capacitor) in a magnetocaloric cooling device. The selected operating concept was then used for active cooling of the battery system.
Abstract
Compact, solid thermal control devices offer a new way to control the intensity and direction of heat flow between the components of a system, which is crucial for both optimized performance and safety. In this work we study a thin, silicon thermal switch capacitor (TSC) used for heat transport in a magnetocaloric cooling system. A numerical model was developed to quantify the effects of various operating conditions and design parameters on the performance of a magnetocaloric device with an embedded TSC. Based on realistic material properties, a maximum cooling-power density of 4000 Wm-2 (2025 ) was obtained for a zero temperature span and an operating frequency of 20 Hz. The use of the presented device was demonstrated on a battery system, motivating further experimental studies to develop a new, compact cooling device that can be directly attached to a heat reservoir, making it desirable for a variety of applications.
Scientific articles
STAR Protocols
Protocol to evaluate a (magneto)caloric device with static thermal switches using a 1D numerical model
We have developed a simple 1D numerical model for simulating a single-stage (magneto)caloric refrigerating device that has static thermal switches (where static refers to those switches whose effective thermal conductivity changes during the on and off states without any moving component). The model serves as a basis for understanding and searching for the optimal parameters for the operation of such a device.
Such a (magneto)caloric device consists of a (magneto)caloric material, two thermal switches, a heat sink, and a heat source. This protocol provides the instructions on how to use the numerical model with either already-provided data or user-provided data. In the first part, we list the required Python packages and required data (properties of all the components and the operating parameters of the device). This is followed by the description of the model (additional information can be found in (Klinar et al. (2022)). The second part of the protocol provides step-by-step instructions for running the simulation: description of the modules and input parameters. The code can be run in two ways: on a PC or on an HPC. This is followed by a presentation of the results, the limitations and the solutions to some problems that might occur.
Two examples of the code with calculated results are available at https://github.com/lahde-unilj/mc_switch, or https://zenodo.org/badge/latestdoi/468418161. In one example, the temperatures in the heat source and the heat sink do not fluctuate during one cycle in the quasi-steady state, while in the other example they do.
Conferences
MRS 2023 Spring
MRS 2023 live again
After a period of virtual MRS meetings, the Spring Meeting 2023 was once again held in person. Around 2000 researchers, engineers and company representatives from all over the world gathered in San Francisco to present the results of their materials research and applications.
Also 6 members of LAHDE laboratory presented their results at the meeting:
– invited lecture held by prof. dr. Andrej Kitanovski (Thermal Management in Caloric Devices),
– dr. Katja Klinar (TCCbuilder: an Open-Source Tool for the Design and Evaluation of Thermal Circuits in Calorics and Other Applications),
– Nada Petelin (Thermal Switch Capacitor in a Magnetocaloric Device).
Conferences
MIDEM 2022
Akademija strojnistva (Academy of Mechanical Engineering 2022)
Thermal Control Elements
Controlling the temperature, intensity, and direction of heat flow between the components of a system, known as thermal management, is crucial for high energy efficiency, optimized performance, high reliability and safety. This is most evident in electronic components that undergo degradation and lose their efficiency if constant and adequate heat dissipation is not ensured. Thermal management is also the key challenge of modern technology in energy production and conversion, transport, and utilisation.
It is becoming evident that conventional thermal management methods like
traditional thermal resistors (i.e. conventional thermal insulation) and
capacitors (conventional thermal storage) cannot meet the requirements for
thermal control in advanced, especially small‐scale systems with higher power
densities or potentially transient, fluctuating or migrating hot or cold spots, and
for temperature-sensitive equipment.
Therefore, elements have been proposed that would allow nonlinear, switchable, and active control of the heat, like their electrical counterparts control electric current. New thermal control elements (TCEs) include thermal conduits, thermal resistors, thermal switches, thermal regulators, thermal
diodes, and thermal capacitors.
Each of the TCEs has a signature functionality: thermal conduits represent solid state routers for heat, thermal resistors have a well-known role of thermal insulation, thermal switches actively control the heat transfer on a small scale by switching between high resistance and low resistance states, thermal regulators and capacitors can maintain a desired temperature, and thermal diodes can rectify heat currents. Implementation of these nonlinear and
switchable TCEs together with a heat source and a heat sink forms thermal control circuits (TCCs) and leads to qualitatively better thermal capabilities, including better regulation or stabilization of temperature, rectification, heterodyning, amplification, regulation, redirection and stabilization of heat flux density, temporary storage of redundant heat, heat scavenging, thermal
computation, etc.
We wanted to take a step forward in advancing the development of novel
thermal management techniques. That lead us to the project whose main goal is to provide researchers and broader society with the World’s first open-source tool for simulation of TCCs that will also serve as a solid foundation for exchange of knowledge in the field of thermal management. The basis for such a tool is a large database of appropriate materials and TCEs already published in the literature. We did a comprehensive literature review to prepare the library, which is available at www.tccbuilder.org.
TCCbuilder: Building thermal control circuits with new numerical tool
Newly emerging thermal control elements (TCEs) and thermal control circuits (TCCs) pave the path to more efficient, focused and reliable thermal management, crucial for optimized performance of power electronics and other systems. We are designing an open-source numerical tool, named TCCbuilder, for building and evaluating TCEs and TCCs, which represents an important bridge between basic research and designing systems that can later be tested and used for real-life applications. We show that the tool in its first stage of development can replicate the behaviour of exemplary TCCs from the literature.
Other events
Cup of Science (Science on the street)
The Renaissance of Thermal Management: from The Invisible Man to Thermal Supercomputers
We attended the public event Cup of Science, organised by Science on the street (Znanost na cesti). These are popular lectures on science for non-scientists, held in public places in the evening. We presented the latest findings related to thermal management, which are interesting for a wider audience.