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

Lead Research Organisation: University of Birmingham
Department Name: Chemical Engineering

Abstract

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.

Planned Impact

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.
 
Description This project we have been developing a design and modelling framework to identify novel designs of latent heat thermal energy storage heat exchangers (LHTES-HEXs). The framework is based on the so-called topology optimization methods (TOP). The latter were used mostly in the field of structural mechanics; the project has extended it use to the field thermal energy storage. The results obtained and presented in a peer-review publication (Energy Journal, 10.1016/j.energy.2019.02.155) shows that the LHTES-HEXs designed with TOP perform 10-20% better (faster charging/discharging). Another publication (Applied Thermal Engineering, 10.1016/j.applthermaleng.2020.115878) has also demonstrated the suitability of metallic 3D printing for fabrication of thermal storage devices. Furthermore, the project has experimentally demonstrated that the complex designs obtained through the TOP framework are suitable for advanced manufacturing methods, in particular 3d printing, opening up mutual opportunities for the heat exchangers industry and the advanced manufacturing industry. 3d printing of topologically optimized LHTES-HEXs has been demonstrated during the project. the devices were manufactured using metallic 3d printing with aluminum powder. The energy storage performance of the device (charging and discharging performance) were tested experimentally using paraffin wax as phase change material. The results form the backbone of the latest conference/journal publications from the project. This is in alignment with the objectives envisioned initially for this project.
Exploitation Route The findings have the potential to be taken forward by academics working in the field of thermal energy storage and mathematical modelling, software developers, thermal energy storage (TES) technology providers and advanced manufacturing industry.

Academics can adopt the TOP methods for advancing other thermal energy storage devices and heat transfer devices, software developer might be interested into incorporating the methods in existing software packages, TES providers can be better informed and supported by the TOP methods during the development of new products, advance manufacturing industry can extend 3d printing application to thermal energy storage market.

The TOP method developed in this project is flexible and can be applied to other high performance energy devices such as fuel cells and thermo-electric devices but also non-energy related devices (e.g. medical devices)
Sectors Aerospace, Defence and Marine,Electronics,Energy,Healthcare,Manufacturing, including Industrial Biotechology

 
Description The modelling methodologies developed for thermal energy storage technologies, have been used to in the following ways: In industry and Society: We have engaged with various companies covering both suppliers and users of thermal energy storage technologies, for example: Renishaw Pcl, Oxford NanoSystems ltd, Sunamp ltd, Integrated Research and Development (IES R&D) and through them new funding has been generated. Collaboration with Calgavin Ltd has been also initiated around topological desing of inserts for heat transfer enhancement in Heat exchangers. This has formed the backbone for Industrial lead grant applications (Innovate UK). Such grant application has been successful (IUK Smart Grant Award) and such collaboration is benefiting from the topological optimization techniques developed in this project. People: the project findings has been contributed directly to deliver to 1 post-doctoral researcher and 1 PhD student advanced skills on topology optimization methods, thermal energy storage technologies and experimental heat transfer. Trough this project the the PI, 1 post-doctoral researcher and 1 PhD student to engage with EPSRC Centre for Doctoral Training in Topological Design (based at the University of Birmingham), opening up new opportunity for the PI to contribute in training of the next generation of topological engineers The early outcomes of this project have been contributed to paving the way for more long term impact across: Society, People and Industry in the UK and internationally
First Year Of Impact 2019
Sector Energy
Impact Types Economic