heat transfer - 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.

Numerical study of macroscopic thermal diodes: influence of interface topography and contact resistance

admin — Mon, 13 Oct 2025 13:02:34 +0000

We continue our exploration of solid-state thermal diodes – a compact, fully passive asset for next-generation thermal management.

Our latest paper, “Numerical study of macroscopic thermal diodes: influence of interface topography and contact resistance,” has just been published in iScience (IF 4.1).

🔍 Key insights:

Interface topography alone has little effect on the rectification factor when contact resistance is negligible. However, it can extend the temperature range of rectification by up to 10 K.

Constant contact resistance tends to reduce rectification. However, when temperature-dependent contact resistance is introduced at low temperatures, rectification can be boosted significantly. In one case, from nearly zero to nearly unity.

These findings provide new guidelines for optimizing solid-state thermal diodes and open up exciting possibilities for practical thermal management applications.

The post Numerical study of macroscopic thermal diodes: influence of interface topography and contact resistance first appeared on Laboratory for refrigeration and district energy.

TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits

admin — Mon, 11 Nov 2024 07:21:40 +0000

Researchers of the LAHDE laboratory of the Faculty of Mechanical Engineering, University of Ljubljana, have developed an open-source tool for 1D modeling of thermal control circuits, TCCbuilder. It is the first tool of its kind that enables quick and easy modeling of thermal control circuits thanks to its graphical user interface and thr associated library of materials used to create thermal control elements.

In addition to the library of materials, there is also a library of already designed thermal control elements from the literature. Researchers from various fields are invited to complement both libraries as well as to add functionality to the tool. Thus, TCCbuilder is not only an indispensable tool for simulations, but also a platform for the exchange of information and networking of researchers in the field of heat transfer and materials.

The tool is presented in the article TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits, which describes the validation and examples of the use of the tool. The article is published in the journal iScience (IF = 4.6), Special Issue: Advanced thermal control: fundamentals and applications.

The article is freely accessible under the following link: https://doi.org/10.1016/j.isci.2024.111263

Summary:

In the area of thermal management, thermal control elements (TCEs) and thermal control circuits (TCCs) are proving to be innovative solutions to the challenges of temperature control and heat dissipation in various applications, ranging from electronic cooling to energy conversion and temperature control in buildings. Their integration promises to improve power density, energy efficiency, system reliability and system life expectancy. With the aim of connecting researchers in the field of thermal management and accelerating the development of TCEs and TCCs, we have developed an open-source TCC simulation tool called TCCbuilder that enables a quick and easy time-dependent 1D numerical analysis of the behavior of TCEs and TCCs. It uses the heat conduction equation to solve temperature profiles in different devices. The TCCbuilder application offers features not previously available with any other TCC modelling tool: a large adjacent library of materials and TCEs as well as a user-friendly graphical user interface (GUI).

The post TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits first appeared on Laboratory for refrigeration and district energy.

Chillventa 2024

admin — Tue, 22 Oct 2024 11:06:29 +0000

From October 8 to 10, the international refrigeration technology trade fair, Chillventa, took place in Nuremberg, bringing together leading companies in the cooling industry, such as Bitzer, Danfoss, Carel, and others.

The event showcased advancements in compressor development (particularly those using CO2 refrigerant), heat exchangers, PCM materials, and much more, including magnetocaloric and electrocaloric refrigerators.

Jakob Perne, a member of our laboratory, attended the fair. The event provided an excellent opportunity to gain insight into industrial developments in this field.

Thank you to all participants and organizers for such an inspiring experience!

The post Chillventa 2024 first appeared on Laboratory for refrigeration and district energy.

International conference of SZE

lahde — Tue, 28 Jun 2022 11:08:47 +0000

We presented our work at the International Conference of SZE:

High-temperature thermal energy storage
Thermoelectric micro heat pump booster for low temperature district heating system
High-temperature heat pumps

Please contact us for more information!

The post International conference of SZE first appeared on Laboratory for refrigeration and district energy.

LAHDE annual report: 2021

lahde — Thu, 06 Jan 2022 16:30:09 +0000

LAHDE Scientific annual report:

Published papers

MAIORINO, Angelo, DEL DUCA, Manuel Gesù, TOMC, Urban, TUŠEK, Jaka, KITANOVSKI, Andrej, APREA, Ciro. A numerical modelling of a multi-layer LaFeCoSi active magnetic regenerator by using artificial neural networks. Applied thermal engineering, ISSN 1359-4311. [Print ed.], Oct. 2021, vol. 197, str. 1-13, ilustr. https://www.sciencedirect. com/science/article/pii/S1359431121008103?utm_campaign=STMJ_AUTH_SERV_PUBLISHED&utm_medium=email&utm_acid=104953246&SIS_ID=&dgcid=STMJ_AUTH_ SERV_PUBLISHED&CMX_ID=&utm_in=DM168036&utm_source=AC_, doi: 10.1016/j.applthermaleng.2021.117375
POREDOŠ Primož, PETELIN, Nada, ŽEL, Tilen, VIDRIH, Boris, GATARIĆ, Pero, KITANOVSKI, Andrej. Performance of the condensation process for water vapour in the presence of a non-condensable gas on vertical plates and horizontal tubes. Energies, ISSN 1996-1073, Apr. 2021, vol. 14, iss. 8, str. 1-28, ilustr. https://www.mdpi.com/1996-1073/14/8/2291, doi: 10.3390/en14082291.
LORBEK, Luka, KATRAŠNIK, Tomaž, KITANOVSKI, Andrej. Impact of neglecting the variations in the relative surface roughnesses of capillary tubes on the accuracy of a capillary tube model. International journal of refrigeration, ISSN 0140-7007. [Print ed.], Sep. 2021, vol. 129, str. 194-203, ilustr. https://www.sciencedirect.com/science/article/pii/S014070072100147X#ack0001, doi: 10.1016/j.ijrefrig.2021.04.022
SWOBODA, Timm, KLINAR, Katja, ABBASI, Shahzaib, BREM, Gerrit, KITANOVSKI, Andrej, MUÑOZ ROJO, Miguel. Thermal rectification in multilayer phase change material structures for energy storage applications. iScience, ISSN 2589-0042, 2021, vol. 24, iss. 8, str. 1-14, ilustr. https://www.sciencedirect.com/science/article/pii/S2589004221008117, doi: 10.1016/j.isci.2021.102843
SWOBODA, Timm, KLINAR, Katja, KITANOVSKI, Andrej, YALAMARTHY, Ananth Saran, MUÑOZ ROJO, Miguel. Solid-state thermal control devices. Advanced electronic materials, ISSN 2199-160X, Mar. 2021, vol. 7, iss. 3, f. 1-28, ilustr. https://onlinelibrary.wiley.com/doi/10.1002/aelm.202000625, doi: 10.1002/aelm.202000625.
KLINAR, Katja, SWOBODA, Timm, MUÑOZ ROJO, Miguel, KITANOVSKI, Andrej. Fluidic and mechanical thermal control devices. Advanced electronic materials, ISSN 2199-160X, Mar. 2021, vol. 7, iss. 3, f. 1-30, ilustr. https://onlinelibrary.wiley.com/doi/10.1002/aelm.202000623, doi: 10.1002/aelm.202000623.
ŠADL, Matej, TOMC, Urban, URŠIČ NEMEVŠEK, Hana. Investigating the feasibility of preparing metal-ceramic multi-layered composites using only the aerosol-deposition technique. Materials, ISSN 1996-1944, Aug. 2021, vol. 14, iss. 16, str. 4548-1-4548-10, ilustr. https://www.mdpi.com/1996-1944/14/16/4548, doi: 10.3390/ma14164548
GATARIĆ, Pero, LORBEK, Luka. Evaluating R450A as a drop-in replacement for R134a in household heat pump tumble dryers. International journal of refrigeration, ISSN 0140-7007. [Print ed.], Aug. 2021, vol. 128, str. 22-33, ilustr. https://www.sciencedirect.com/science/article/pii/S0140700721001195, doi: 10.1016/j.ijrefrig.2021.03.020.
AHČIN, Žiga, LIANG, Jierong, ENGELBRECHT, Kurt, TUŠEK, Jaka. Thermo-hydraulic evaluation of oscillating-flow shell-and-tube-like regenerators for (elasto)caloric cooling. Applied thermal engineering, ISSN 1359-4311. [Print ed.], May 2021, vol. 190, str. 1-15, ilustr. https://www.sciencedirect.com/science/article/pii/S135943112100291X, doi: 10.1016/j.applthermaleng.2021.116842.
MAIORINO, Angelo, DEL DUCA, Manuel Gesù, TOMC, Urban, TUŠEK, Jaka, KITANOVSKI, Andrej, APREA, Ciro. A numerical modelling of a multi-layer LaFeCoSi active magnetic regenerator by using artificial neural networks. Applied thermal engineering, ISSN 1359-4311, Oct. 2021, vol. 197, str. 1-13, ilustr. https://www.sciencedirect. com/science/article/pii/S1359431121008103?utm_campaign=STMJ_AUTH_SERV_PUBLISHED&utm_medium=email&utm_acid=104953246&SIS_ID=&dgcid=STMJ_AUTH_ SERV_PUBLISHED&CMX_ID=&utm_in=DM168036&utm_source=AC_, doi: 10.1016/j.applthermaleng.2021.117375.
PORENTA, Luka, LAVRENČIČ, Marko, DUJC, Jaka, BROJAN, Miha, TUŠEK, Jaka, BRANK, Boštjan. Modeling large deformations of thin-walled SMA structures by shell finite elements. Communications in Nonlinear Science and Numerical Simulation, ISSN 1007-5704, okt. 2021, vol. 101, no. 105897, str. 1-29, ilustr. https://repozitorij.uni-lj.si/IzpisGradiva.php?id=127201, doi: 10.1016/j.cnsns.2021.105897.
MASCHE, M., IANNICIELLO, Lucia, TUŠEK, Jaka, ENGELBRECHT, Kurt. Impact of hysteresis on caloric cooling performance. International journal of refrigeration, ISSN 0140-7007. [Print ed.], Jan. 2021, vol. 121, str. 302-312, ilustr. https://www.sciencedirect.com/science/article/pii/S0140700720304229?via%3Dihub#!, doi: 10.1016/j.ijrefrig.2020.10.012.
NAVICKAITE, Kristina, IANNICIELLO, Lucia, TUŠEK, Jaka, ENGELBRECHT, Kurt, BAHL, Christian Robert Haffenden, PENZEL, Michael, NESTLER, Klaus, BÖTTGER-HILLER, Falko, ZEIDLER, Henning. Plasma electrolytic polishing of nitinol : investigation of functional properties. Materials, ISSN 1996-1944, Oct. 2021, vol. 14, iss. 21, str. 1-13, ilustr. https://www.mdpi.com/1996-1944/14/21/6450, doi: 10.3390/ma14216450.

Granted patent

Micro-magnetocaloric device EP3106781B1

New projects

TCCbuilder: Odprtokodno simulacijsko orodje za toplotne tokokroge
Novo MHD-toplotno stikalo za nekonvencionalni magnetni hladilni sistem (MHD magcool), BI-DE/21-22-008

Conferences

KITANOVSKI, Andrej. The future of magnetic refrigeration and heat pumping. V: Advances in magnetics 2020-21 : June 13-16, 2021 : book of abstracts. [New York: IEEE]. 2021, str. [68]. http://aim2020.poliba.it/wordpress/program/program-overview/?fbclid=IwAR2pXtjkBn1cwQUsqf13mXZsPKhM20tkwMYFIExuG5751nff6RqN9CpeUTg.
NOSAN, Simon, TOMC, Urban, KLINAR, Katja, KITANOVSKI, Andrej. New concept of electromagnetic field source for magnetic refrigeration. V: Book of abstracts : CHC Eurotherm Seminar, July 13-15, 2021. [S.l.]: Eurotherm. 2021, str. [4]. https://eurotherm.et.utwente.nl/index.php/book-of-abstracts/.
TOMC, Urban, DALL´OLIO, Stefano, KLINAR, Katja, NOSAN, Simon, ERJAVEC, Urška, ŠADL, Matej, URŠIČ NEMEVŠEK, Hana, KITANOVSKI, Andrej. Cool future: magnetocaloric devices based on static and rare earth free magnetic field sources. V: Book of abstracts : CHC Eurotherm Seminar, July 13-15, 2021. [S.l.]: Eurotherm. 2021, str. [5]. https://eurotherm.et.utwente.nl/index.php/book-of-abstracts/.
SWOBODA, Timm, KLINAR, Katja, KITANOVSKI, Andrej, MUÑOZ ROJO, Miguel. High asymmetric heat transport in multilayer phase change materials. V: 2021 Virtual MRS Spring Meeting & Exhibit : April 17-23, 2021. [Warrendale (PA)]: Materials Research Society. 2021, str. [629-630]. https://www.mrs.org/docs/default-source/meetings-events/spring-meetings/2021/abstract-book.pdf?sfvrsn=66f9da0c_2, https://www.mrs. org/meetings-events/spring-meetings-exhibits/2021-mrs-spring-meeting/call-for-papers/symposium-sessions-detail?code=NM08.
DALL´OLIO, Stefano, TOMC, Urban, KLINAR, Katja, KITANOVSKI, Andrej. Design, enhanced thermal and flow efficiency of an active magnetic regenerator. V: Advances in magnetics 2020-21 : June 13-16, 2021 : book of abstracts. [New York: IEEE]. 2021, str. [72]. http://aim2020.poliba.it/wordpress/program/program-overview/?fbclid=IwAR2pXtjkBn1cwQUsqf13mXZsPKhM20tkwMYFIExuG5751nff6RqN9CpeUTg.
NOSAN, Simon, TOMC, Urban, KLINAR, Katja, KITANOVSKI, Andrej. New concept of electromagnetic field sourcefor magnetic refrigeration. V: Advances in magnetics 2020-21 : June 13-16, 2021 : book of abstracts. [New York: IEEE]. 2021, str. [192]. http://aim2020.poliba.it/wordpress/program/program-overview/?fbclid=IwAR2pXtjkBn1cwQUsqf13mXZsPKhM20tkwMYFIExuG5751nff6RqN9CpeUTg.
KLINAR, Katja, VOZEL, Katja, KITANOVSKI, Andrej. Numerical tool for evaluation of static thermal switches in caloric refrigeration and heat pumping. V: Book of abstracts : CHC Eurotherm Seminar, July 13-15, 2021. [S.l.]: Eurotherm. 2021, str. [40]. https://eurotherm.et.utwente.nl/index.php/book-of-abstracts/.
POREDOŠ, Primož, MAROVT, Franc, KITANOVSKI, Andrej, POREDOŠ, Alojz. Analiza izboljšanja energetske učinkovitosti toplotne črpalke zrak-voda z glikolskim prenosnikom toplote = Analysis of energy efficiency improvement of air water heat pump with glycol heat exchanger. V: Mednarodna konferenca SZE : Oskrba ter raba energije v pametni stavbi in domu : Portorož, 28.-29. junij 2021 = International Conference of SZE : Energy supply and use in smart buildings and homes : Portorož, 28.-29. June 2021 : zbornik prispevkov. Ljubljana: Slovensko združenje za energetiko. 2021, str. 78-79, ilustr.
GATARIĆ, Pero, POREDOŠ, Primož, KITANOVSKI, Andrej. Analiza izboljšanja energetske učinkovitosti sušilnega stroja s toplotno črpalko z uporabo okolju prijaznejšega hladiva R450A = Improving the energy efficiency of a heat pump dryer using the environmentally friendly refrigerant R450A. V: Mednarodna konferenca SZE : Oskrba ter raba energije v pametni stavbi in domu : Portorož, 28.-29. junij 2021 = International Conference of SZE : Energy supply and use in smart buildings and homes : Portorož, 28.-29. June 2021 : zbornik prispevkov. Ljubljana: Slovensko združenje za energetiko. 2021, str. 96-97, ilustr.
DALL´OLIO, Stefano, TOMC, Urban, KLINAR, Katja, NOSAN, Simon, KITANOVSKI, Andrej. Unconventional magnetocaloric wine cooler initial performance. V: THERMAG IX : 9th IIR International Conference on Caloric Cooling and Applications of Caloric Materials : virtual conference, June 7-11, 2021, College Part, Maryland, USA, str. 120. https://files.constantcontact.com/8d76dc76201/86788d2d-77ec-4dfa-9ca9-894a21e814d5.pdf.
TOMC, Urban, ŠADL, Matej, KLINAR, Katja, URŠIČ NEMEVŠEK, Hana, KITANOVSKI, Andrej. Digital microfluidics in magnetocaloric cooling. V: THERMAG IX : 9th IIR International Conference on Caloric Cooling and Applications of Caloric Materials : virtual conference, June 7-11, 2021, College Part, Maryland, USA, str. 128. https://files.constantcontact.com/8d76dc76201/86788d2d-77ec-4dfa-9ca9-894a21e814d5.pdf.
KUHELJ, Anja, SIMONIČ, Jasmina, DALL´OLIO, Stefano, KLINAR, Katja, PETELIN, Nada, KITANOVSKI, Andrej, MENCINGER, Jure, DREN, Dejan, BAČ, Vladimir. Enostavno orodje za določanje razporeditve cevi “skin” kondenzatorja na hladilnih aparatih = Simple tool for determining the pipe arrangement in the skin condenser for household refrigerators. V: Mednarodna konferenca SZE : Oskrba ter raba energije v pametni stavbi in domu : Portorož, 28.-29. junij 2021 = International Conference of SZE : Energy supply and use in smart buildings and homes : Portorož, 28.-29. June 2021 : zbornik prispevkov. Ljubljana: Slovensko združenje za energetiko. 2021, str. 92-93,
IANNICIELLO, Lucia, TUŠEK, Jaka, MAÑOSA, Lluís, VIVES, Eduard, ENGELBRECHT, Kurt. Elastocaloric materials for active cooling regenerators. V: Book of abstracts : CHC Eurotherm Seminar, July 13-15, 2021. [S.l.]: Eurotherm. 2021, str. [7]. https://eurotherm.et.utwente.nl/wp-content/uploads/2021/07/bookofabstracts1.pdf.
AHČIN, Žiga, LIANG, Jierong, ENGELBRECHT, Kurt, TUŠEK, Jaka. Thermo-hydraulic analysis of shell-and-tube-like geometries for elastocaloric regenerators. V: Book of abstracts : CHC Eurotherm Seminar, July 13-15, 2021. [S.l.]: Eurotherm. 2021, str. [11]. https://eurotherm.et.utwente.nl/index.php/book-of-abstracts/.
IANNICIELLO, Lucia, TUŠEK, Jaka, ENGELBRECHT, Kurt. Updated design of an active elastocaloric regenerator. V: THERMAG IX : 9th IIR International Conference on Caloric Cooling and Applications of Caloric Materials : virtual conference, June 7-11, 2021, College Part, Maryland, USA, str. 52. https://files.constantcontact.com/8d76dc76201/86788d2d-77ec-4dfa-9ca9-894a21e814d5.pdf.
MASCHE, M., IANNICIELLO, Lucia, TUŠEK, Jaka, ENGELBRECHT, Kurt. Numerical modelling of hysteresis in caloric materials for solid-state cooling. V: THERMAG IX : 9th IIR International Conference on Caloric Cooling and Applications of Caloric Materials : virtual conference, June 7-11, 2021, College Part, Maryland, USA, str. 100. https://files.constantcontact.com/8d76dc76201/86788d2d-77ec-4dfa-9ca9-894a21e814d5.pdf.
PORENTA, Luka, KABIRIFAR, Parham, ŽEROVNIK, Andrej, ČEBRON, Matjaž, ŽUŽEK, Borut, BROJAN, Miha, TUŠEK, Jaka. Durable elastocaloric effect in thin walled Ni-Ti tubes. V: THERMAG IX : 9th IIR International Conference on Caloric Cooling and Applications of Caloric Materials : virtual conference, June 7-11, 2021, College Part, Maryland, USA, str. 130. https://files.constantcontact.com/8d76dc76201/86788d2d-77ec-4dfa-9ca9-894a21e814d5.pdf.

Awards

Rector’s Award for the best innovation 2021 for EASE

The post LAHDE annual report: 2021 first appeared on Laboratory for refrigeration and district energy.

CHC Caloric Heating and Cooling seminar, Twente 2020

lahde — Wed, 28 Jul 2021 05:16:22 +0000

Eurotherm CHC (Caloric Heating and Cooling) 2020 is another scientific seminar that was postponed from last year to 2021. It took place virtually between 13 and 15 July. The LAHDE laboratory participated in 4 conference papers and an invited lecture:

Cool future: magnetocaloric devices based on static and rare earth free
magnetic field sources (Urban Tomc, Stefano Dall’Olio, Katja Klinar, Simon Nosan, Urška Erjavec, Matej Šadl, Hana Uršič, Andrej Kitanovski)
New concept of electromagnetic field source for magnetic refrigeration (Simon Nosan, Urban Tomc, Katja Klinar, Andrej Kitanovski)
Numerical tool for evaluation of static thermal switches in caloric
refrigeration and heat pumping (Katja Klinar, Katja Vozel, Andrej Kitanovski)
Elastocaloric materials for active cooling regenerators (Lucia Ianniciello, Jaka Tušek, Lluid Manosa, Eduard Vives, Kurt Engelbrecht)
Thermo-hydraulic analysis of shell-and-tube-like geometries for
elastocaloric regenerators (Žiga Ahčin, Jierong Liang, Kurt Englebrecht, Jaka Tušek)

Seminar information: https://eurotherm.et.utwente.nl/#page

The post CHC Caloric Heating and Cooling seminar, Twente 2020 first appeared on Laboratory for refrigeration and district energy.

Performance of the Condensation Process on Vertical Plates and Horizontal Tubes

lahde — Wed, 05 May 2021 08:02:12 +0000

The condensation of humid air is a crucial step in air conditioning and process engineering. However, the models that describe the condensation of vapour in the presence of a non-condensable gas require time-consuming numerical calculations that go beyond the Nusselt film theory. Only a small number of publications exist, where simple and computationally effective correlations for the condensation of water vapour in the presence of air are presented for specially designed condenser heat exchangers. Therefore, the objective of this paper is to extend the existing semi-empirical correlations for different geometries and process parameters. For the purpose of the study, an experimental setup with two different condenser heat exchangers based on vertical plates (height 74 mm) and horizontal tubes (3 tubes, diameter 40 mm and 7 tubes, diameter 15 mm) was built. Additionally, based on existing correlations, we developed two semi-empirical models that predict the condensation mass flux for the proposed geometries. Here, we report that the agreement between the experimental and theoretical values predicted by the new, semi-empirical correlations is excellent, with an average uncertainty of less than ±6%. Their usability was demonstrated by a possibly significant performance improvement of the condenser inside a condensation-type tumble dryer.

LINK: https://www.mdpi.com/1996-1073/14/8/2291

The post Performance of the Condensation Process on Vertical Plates and Horizontal Tubes first appeared on Laboratory for refrigeration and district energy.

Numerical and experimental investigation of roll-bond heat exchangers in ST, PV and PV/T modules (Energy Conversion and Management journal, IF 7.181)

lahde — Mon, 16 Mar 2020 11:47:46 +0000

The article: Numerical and experimental investigation of the energy and exergy performance of solar thermal, photovoltaic and photovoltaic-thermal modules based on roll-bond heat exchangers

has been published in Energy Conversion and Management journal (IF = 7.181, 2019, top 5%).

Link to the article*: https://authors.elsevier.com/c/1akEjin8VZz4e.

Abstract:

This paper presents numerical and experimental energy and exergy performance assessments of solar thermal (ST), photovoltaic (PV) and photovoltaic/thermal (PV/T) modules based on roll-bond heat exchangers having three different channel geometries: serial, parallel and bionic. The validation of a coupled numerical simulation encompassing the thermo-hydraulic and electrical properties shows that 78% of all the data lies within a ± 10% uncertainty. The thermo-hydraulic simulation shows that the lowest outlet-water temperature inside the absorber is for the case of the bionic absorber (average 44.1 °C vs. 46.5 °C for the serial). This geometry is also beneficial when considering pressure losses, since compared to the parallel configuration (average 778 Pa) the bionic has significantly lower pressure losses (average 385 Pa). The simulation of the electrical properties of PV/T with all three absorber types showed the highest average solar-to-electrical efficiency (14.5%) in the case of the bionic absorber compared to the PV/T with parallel and serial absorbers (14.4% and 14.3%, respectively). Finally, a set of experiments using the ST, PV and PV/T2 (the index 2 denotes a PV/T collector variant with a foil thickness of 0.3 mm, compared to the thickness of 0.4mm for PV/T1, positioned between the absorber and the PV cells) modules showed that the PV module, coupled with a bionic absorber plate, achieves the highest average electrical (PV – 8.5% vs. PV/T2 – 9.9%) and exergy (ST – 4.4% vs. PV – 9.2% vs. PV/T2 – 12.7%) efficiencies. Only in terms of the thermal efficiency, the PV/T is at a disadvantage to the ST (PV/T2 – 33.5% vs. ST – 61.4%) due to the air gap between the front glass and the absorber of the latter module.

*Full article is available before the May 3^rd 2020. No sign up, registration or fees are required.

The post Numerical and experimental investigation of roll-bond heat exchangers in ST, PV and PV/T modules (Energy Conversion and Management journal, IF 7.181) first appeared on Laboratory for refrigeration and district energy.