Topology Optimization for Additive manufacturing of thermal storage heat exchangers with PCMs (TopAddPCM)

UK has committed to an ambitious decarbonisation plan: reduce CO2 emissions by 80% by 2050 - a dramatic transformation of our energy system. Decarbonisation of the electricity sector is expected by 2030. However, meeting the targets will be impossible if decarbonisation of heat is not tackled. More than half of UK finial energy use is due to heating and cooling, which accounts for about 30% of CO2 emissions. This will require the introduction of low carbon alternatives - wind and solar energy in particular. However, such a shift poses major challenges including the imbalance between supply and demand, congestion of energy networks and in ultimate analysis the need of a more flexible energy system. Thermal energy storage (TES) has the potential to provide a solution to these challenges by capturing excess heat, time-shifting heat demand and increasing the use of renewable sources.

Among the TES technologies, latent heat thermal energy storage (LHTES) is seen as one of the most promising; LHTES uses phase change materials (PCMs) and it stores/releases thermal energy during a solid to liquid phase transition of the PCM. As our ability of storing thermal energy efficiently depends significantly on the design of the heat exchangers enclosing the PCMs, a great attention has been drawn to designing new LHTES heat exchangers that outperform current state-of-the art ones. To devise the LHTES heat exchangers of the future, thinking of advanced design methods - coupled with proper manufacturing techniques - is urgently necessary.

The proposed research - involving energy storage, computational methods, heat & mass transfer and manufacturing technologies - aims to i) establish a generalized route to designing thermal energy storage systems with PCMs using topology optimization methods and to ii) link the designing route with metal additive manufacturing methods. This project will therefore offer an innovative numerical design methodology and will generate experimental evidences that will allow a robust validation of the proposed method.

This proposal is highly relevant for the UK research and industry in the energy sector; in particular i) It will help researchers to develop thermal energy storage systems faster and more accurately; in doing so it will enable faster deployment of low carbon technologies ii) it will support UK in maintaining a leading role in the field of energy storage - one of the pillar technologies identified by the UK's government industrial strategy iii) it will test additive manufacturing in the novel context of thermal energy storage; therefore it will offer the opportunity of a new market sector for additive manufacturing products.

This project aims to establish and validate experimentally a generalized method - based on topology optimization - for designing thermal energy storage (TES) systems with phase change materials (PCMs). The method will enable to configure TES systems with PCMs that outperform state-of-the-art designs. By bringing together energy storage, computational methods, heat & mass transfer and manufacturing technologies, this project will have a profound academic, societal and economic impact, contributing to the UK decarbonisation plan.

Academics will be able to use the design method proposed in this project to develop TES with PCMs more rapidly, more accurately and with better performance. This will initially occur through the transfer of knowledge to UK, EU and US research partners of this project. They will be able to include the methodology develop in this project into their research on thermal energy storage and on topology optimization methods. For the first time the academic community of thermal energy storage and the one of topology optimization method will join under the umbrella of this project, enabling impact beyond the field of energy engineering.

The academic knowledge that the project generates will lead to industrial and strategic impact. By bringing new approaches in design methods for thermal energy storage systems, the project will enable faster deployment of renewable heat and advanced low carbon technologies, such as solar thermal, heat pumps and micro-cogeneration plants. The links with the industrial partner in the field of additive manufacturing - Renishaw - will enable the impact of this project on the economy. Knowledge on topology optimization generated in this project will perfectly match the need of advanced methods for designing components fabricated by additive manufacturing. Moreover, this project will test additive manufacturing in a novel application context - thermal energy storage - thus, it will offer the opportunity of a new market sector for additive manufacturing products.

Finally, the industrial and strategic impact will result in relevant societal impact. Novel and efficient TES systems will facilitate the deployment of low carbon energy technologies - due to the enabling effect of thermal energy storage technology - which will result in reduction CO2 emissions, thus contributing to achieve the decarbonisation of the UK energy system - one of our paramount societal challenges. In doing so this project will contribute to the UK economy, by promoting jobs in renewable energy systems, and will improve health by contributing to reduce CO2 emission.