Periodic Reporting for period 1 - MAX4LES (Analysis of Molten Salt-Air Heat Exchangers for Large Scale Energy Storage Technologies)
Período documentado: 2023-09-01 hasta 2025-08-31
The MAX4LES project addressed a critical challenge in Europe’s clean energy transition: predicting mitigation strategies for the solidification of molten salts inside air-cooled shell and tube heat exchangers used in large-scale thermal energy storage systems. Molten salts are essential for technologies such as concentrated solar power (CSP) plants, pumped thermal energy storage (PTES) systems, liquid air energy storage (LAES) systems, and other high-temperature industrial processes due to their high heat capacity and cost-effectiveness. However, their high freezing point makes them vulnerable under abnormal operating conditions, such as pump failure, heat tracing malfunction, or sudden drops in temperature. In such scenarios, molten salts can solidify in the tubes of shell and tube heat exchangers leading to blockages, efficiency losses, and costly operational interruptions. These risks ultimately threaten the reliability and economic viability of large-scale energy storage solutions.
This project sets out to develop scientific benchmarks, design and operational strategies to prevent salt solidification in molten salt-air shell and tube heat exchangers by combining advanced numerical modelling, comparative performance studies, and trace heating evaluations. By advancing a computational proof-of-concept for solidification prevention measures, the project lays the foundation for future experimental validation and industrial adoption. Addressing solidification risks brings multiple advantages: (i) it enhances the system reliability by reducing unplanned outages, (ii) improves economic viability by avoiding costly downtime and maintenance, and (iii) strengthens societal benefits by enabling greater penetration of renewable energy into the power grid.
This work directly supports the EU Renewable Energy Directive (RED II) and the European Green Deal by enabling more reliable, efficient, and cost-effective renewable energy systems. In the long term, the results contribute to Europe’s ambition to achieve climate neutrality by 2050, while strengthening the competitiveness of European industries in clean energy technologies.
This project sets out to develop scientific benchmarks, design and operational strategies to prevent salt solidification in molten salt-air shell and tube heat exchangers by combining advanced numerical modelling, comparative performance studies, and trace heating evaluations. By advancing a computational proof-of-concept for solidification prevention measures, the project lays the foundation for future experimental validation and industrial adoption. Addressing solidification risks brings multiple advantages: (i) it enhances the system reliability by reducing unplanned outages, (ii) improves economic viability by avoiding costly downtime and maintenance, and (iii) strengthens societal benefits by enabling greater penetration of renewable energy into the power grid.
This work directly supports the EU Renewable Energy Directive (RED II) and the European Green Deal by enabling more reliable, efficient, and cost-effective renewable energy systems. In the long term, the results contribute to Europe’s ambition to achieve climate neutrality by 2050, while strengthening the competitiveness of European industries in clean energy technologies.
Over the course of the fellowship, MAX4LES carried out a range of technical, scientific, management, training, and dissemination activities to meet its objectives:
Technical and scientific work:
a. Developed and validated high-fidelity computational fluid dynamics (CFD) models to simulate heat transfer and fluid behavior in molten salt–air shell and tube heat exchangers.
b. Analyzed solidification behavior under abnormal operating conditions to identify factors that trigger the onset of molten salt solidification.
c. Established quantitative benchmarks for evaluating two flow configurations and identified the optimal arrangement for enhanced thermal performance.
d. Evaluated trace heating strategies to prevent solidification during abnormal scenarios and demonstrated their contribution to improving system reliability.
Project management
a. Developed a comprehensive project plan and ensured effective project management and coordination.
b. Prepared a data management plan (DMP), in line with EU requirements for open-access and FAIR data principles.
c. Designed a career development plan (CDP) to align research activities with long-term professional goals and skills development.
d. Prepared a dissemination, exploitation, and communication activity plan in line with EU requirements.
Training and collaboration
The project included a secondment at Eindhoven University of Technology (TU/e) with Prof. Camilo Rindt, collaboration with industrial partner Aalborg CSP, and advanced training at the Technical University of Denmark (DTU), including:
a. A four-day Teaching Lab course at DTU.
b. A two-week Optimization Methods for Energy System Studies course under the EIT HEI initiative.
c. Danish language training for professional social integration.
Dissemination activities
MAX4LES disseminated its findings widely through peer-reviewed journals and international conferences:
a. One journal article in ASME Journal of Energy Resources and Technology Part A: Sustainable Renewable Energy (IF: 2.4).
b. One publication in the Proceedings of the 18th International Conference on Energy Sustainability (ASME ES 2024), Anaheim, USA.
c. One conference oral presentation at the 28th International Conference on Process Integration, Modelling and Optimization for Energy Savings and Pollution Reduction (PRES'25), Port Dickson, Malaysia.
d. One journal article in Energy Conversion and Management, Elsevier (IF: 10.9).
e. Numerical models and datasets supporting the findings are documented in the journal publications and they can be made available upon request to ensure scientific reproducibility while safeguarding future research and potential exploitation opportunities.
Additionally, two papers will be published shortly in peer-reviewed, top international journals targeting researchers in the fields of renewable energy and thermal energy storage. The project activities have been disseminated by social media (e.g. LinkedIn, ResearchGate) and the project website (DTU Orbit). The dissemination strategy of MAX4LES was designed to maximize the visibility, accessibility, and impact of the project’s results across academic, industrial, and policy communities, aligning with the MSCA Postdoctoral Fellowship objectives and the Horizon Europe principles of open science and societal impact.
Technical and scientific work:
a. Developed and validated high-fidelity computational fluid dynamics (CFD) models to simulate heat transfer and fluid behavior in molten salt–air shell and tube heat exchangers.
b. Analyzed solidification behavior under abnormal operating conditions to identify factors that trigger the onset of molten salt solidification.
c. Established quantitative benchmarks for evaluating two flow configurations and identified the optimal arrangement for enhanced thermal performance.
d. Evaluated trace heating strategies to prevent solidification during abnormal scenarios and demonstrated their contribution to improving system reliability.
Project management
a. Developed a comprehensive project plan and ensured effective project management and coordination.
b. Prepared a data management plan (DMP), in line with EU requirements for open-access and FAIR data principles.
c. Designed a career development plan (CDP) to align research activities with long-term professional goals and skills development.
d. Prepared a dissemination, exploitation, and communication activity plan in line with EU requirements.
Training and collaboration
The project included a secondment at Eindhoven University of Technology (TU/e) with Prof. Camilo Rindt, collaboration with industrial partner Aalborg CSP, and advanced training at the Technical University of Denmark (DTU), including:
a. A four-day Teaching Lab course at DTU.
b. A two-week Optimization Methods for Energy System Studies course under the EIT HEI initiative.
c. Danish language training for professional social integration.
Dissemination activities
MAX4LES disseminated its findings widely through peer-reviewed journals and international conferences:
a. One journal article in ASME Journal of Energy Resources and Technology Part A: Sustainable Renewable Energy (IF: 2.4).
b. One publication in the Proceedings of the 18th International Conference on Energy Sustainability (ASME ES 2024), Anaheim, USA.
c. One conference oral presentation at the 28th International Conference on Process Integration, Modelling and Optimization for Energy Savings and Pollution Reduction (PRES'25), Port Dickson, Malaysia.
d. One journal article in Energy Conversion and Management, Elsevier (IF: 10.9).
e. Numerical models and datasets supporting the findings are documented in the journal publications and they can be made available upon request to ensure scientific reproducibility while safeguarding future research and potential exploitation opportunities.
Additionally, two papers will be published shortly in peer-reviewed, top international journals targeting researchers in the fields of renewable energy and thermal energy storage. The project activities have been disseminated by social media (e.g. LinkedIn, ResearchGate) and the project website (DTU Orbit). The dissemination strategy of MAX4LES was designed to maximize the visibility, accessibility, and impact of the project’s results across academic, industrial, and policy communities, aligning with the MSCA Postdoctoral Fellowship objectives and the Horizon Europe principles of open science and societal impact.
MAX4LES delivered new insights that advance knowledge beyond the current state of the art:
a. Developed validated CFD models capable of predicting the onset of salt solidification, with accuracy verified against published benchmark data.
b. Quantified the influence of operating parameters, such as inlet temperature, inlet pressure, mass flow rate, and thermophysical properties on the risk of salt solidification, establishing critical thresholds for safe operation.
c. Identified critical zones prone to salt freezing under the tested design and operating conditions.
d. Conducted comparative performance assessment of two heat exchanger designs, showing 13-18 % variation in thermal effectiveness under selected operating conditions, thereby providing quantitative guidance for future industrial design.
To fully exploit these results, the following steps are required:
a. Experimental validation of computational findings.
b. Industrial partnerships to advance the technology readiness level (TRL) from TRL3 to higher levels.
c. Integration into EU-funded demonstration projects for large-scale CSP and PTES technologies.
d. Engagement with regulatory bodies for future standardization efforts to support industrial adoption.
These results will benefit academic researchers, energy system designers, and industrial stakeholders engaged in developing next-generation thermal energy storage technologies. The outcomes will strengthen the competitiveness of European renewable energy industries, lower operational risks, and facilitate faster integration of renewable energy into the power grid. In the long term, the findings will also support the decarbonization of energy-intensive sectors such as hydrogen production, advanced nuclear reactor systems, and other high-temperature industrial applications.
a. Developed validated CFD models capable of predicting the onset of salt solidification, with accuracy verified against published benchmark data.
b. Quantified the influence of operating parameters, such as inlet temperature, inlet pressure, mass flow rate, and thermophysical properties on the risk of salt solidification, establishing critical thresholds for safe operation.
c. Identified critical zones prone to salt freezing under the tested design and operating conditions.
d. Conducted comparative performance assessment of two heat exchanger designs, showing 13-18 % variation in thermal effectiveness under selected operating conditions, thereby providing quantitative guidance for future industrial design.
To fully exploit these results, the following steps are required:
a. Experimental validation of computational findings.
b. Industrial partnerships to advance the technology readiness level (TRL) from TRL3 to higher levels.
c. Integration into EU-funded demonstration projects for large-scale CSP and PTES technologies.
d. Engagement with regulatory bodies for future standardization efforts to support industrial adoption.
These results will benefit academic researchers, energy system designers, and industrial stakeholders engaged in developing next-generation thermal energy storage technologies. The outcomes will strengthen the competitiveness of European renewable energy industries, lower operational risks, and facilitate faster integration of renewable energy into the power grid. In the long term, the findings will also support the decarbonization of energy-intensive sectors such as hydrogen production, advanced nuclear reactor systems, and other high-temperature industrial applications.