Advances in manufacturing technology are allowing the development of smaller, more powerful electronic components such as microprocessors and power modules. This has allowed and is continuing to drive innovation in a range of areas including high performance computing, artificial intelligence, robotics, electric vehicles, renewable energy generators, and communication devices. However, the increasing power density also leads to cooling problems, and the amount of heat per unit area which must be removed is rapidly increasing beyond the capabilities of existing cooling systems. Hence, there is an urgent need to develop next-generation cooling systems capable of cooling future electronic devices in order to prevent bottle-necking of their development. This is reflected in the market for heat sink manufacture, which is expected to grow to $15.4bn globally by 2024. In this project we will develop "intensified" liquid-phase cooling systems: using dynamic flow and novel channel design to significantly enhance the maximum rate of heat removal. In collaboration with key industrial partners we will consider the use of advanced manufacturing technologies, including 3D printing, in order to develop heat sink geometries which are at the forefront of technological and manufacturing capability. This, in conjunction with the use of dynamic flow, will allow us to maximise heat removal rates without significant energy penalty. Further, we will test our technology on cutting edge power electronics circuits in order to provide validation of our design concepts and evidence of the near-to-market impact potential of the research. The results of this research will allow effective cooling and the possibility of heat re-use from future, highly powered, electronic devices. This will enable future developments in small and micro electronics, allowing future innovation in the application areas listed above which are crucial in the drive for a greener, more productive and more resilient nation.

In the UK, heat accounts for over a third of the nation's greenhouse gas emissions. Most of the heating and cooling in our industries and buildings are delivered directly or indirectly by fossil fuels. Apart from the greenhouse emissions, the extensive consumption of fossil fuels can also lead to a large depletion of energy resources, waste heat production and pollution to the surrounding environment. To meet the target of Net Zero greenhouse gas emissions by 2050, there is an urgent need for decarbonising heating and cooling by utilising renewable energy and industrial waste heat with advanced technologies. Compared to renewable energy such as solar, the resources from industrial waste heat have clear advantages including greater stabilisation, less cost and larger temperature ranges. Therefore, industrial waste heat recovery for decarbonised heating and cooling is an attractive concept that could simultaneously reduce fossil fuel consumption and CO2 emissions. Evidently, in the UK, based on a recent report, it was identified that around 48 TWh/yr industrial waste heat sources were available of which about 28 TWh/yr could be potentially used to meet the heating and cooling demands. All heat-intensive industrial sectors including iron & steel, refineries, ceramics, glass, cement, chemicals, food and drink, paper and pulp can contribute to this potential. Even so, high efficient energy conversion systems need to be designed and applied so as to maximize the waste heat utilisations for heating and cooling. On the other hand, the locations of industrial waste heat providers such as steel plants are mostly far away from the utilisers for heating and cooling. Conventionally, hot water heated by the industrial waste heat is transported through long distance water pipe to the end user site which can cause huge pump power consumption and heat losses due to significant friction pressure drop for the water flow and large temperature difference between water flow and ambient. There are therefore challenges to the long-distance waste heat transport and high-efficient and innovative energy conversion technologies for the decarbonising heating and cooling. To address these challenges, in this proposal, strategies for a novel concept of decarbonising district heating and cooling system (H2-heat) will be developed with the integration of metal hydride (MH) heat pump on site, long distance hydrogen and heat transport, and MH heating and cooling for end users. In such a system, low grade heat (~210C) and extra low grade heat (~40C) from TATA Steel plant or a similar industry site will be used as heat sources while building heating and cooling spaces are applied as heat sink and low temperature heat source respectively at end user side. Technologies of MH heat pump, a thermal driven chemical compressor with MH, long distance hydrogen and heat transport, MH space heating and cooling, MH alloys and reactors applied in the systems and processes, controls for space heating and cooling etc. will be identified and investigated. Ultimately, a decarbonising district heating and cooling test system with industrial waste heat from TATA Steel plant or other industrial sites will be constructed in lab with 5 kWth heating or cooling capacity and high heat transport efficiency. Furthermore, a detailed mathematical model will be developed and validated for the established system; this can be used for a system scale-up into actual application in TATA Steel plant or other industrial sites where low grade waste heat is available. As yet, no research activity on such a system can be found either nationally or internationally. Important reasons include the difficulty in choosing a thermal driven long distance hydrogen and heat transport system and associated MH alloys for space heating and cooling and complicated designs of MH reactors in the H2-heat system. These challenges and issues will be addressed and solved by this proposed project.

A hydrogen economy has been the focus of researchers and developers over the decades. However, the complexity of moving and storing hydrogen has always been a major obstacle to deploy the concept. Therefore, other materials can be employed to improve handling whilst reducing cost over long distances and long periods. Ammonia, a highly hydrogenated molecule, can be used to store and distribute hydrogen easily, as the molecule has been employed for more than 120 years for fertilizer purposes. Being a carbon-free chemical, ammonia (NH3) has the potential to support a hydrogen transition thus decarbonising transport, power and industries. However, the complexity of using ammonia for power generation lays on the appropriate use of the chemical to reach high power outputs combined with currently low efficiencies that bring up overall costs. This complex scenario is also linked to the production of combustion profiles that tend to be highly polluting (with high NOx emissions and slipped unburned ammonia). There is no technology capable of using ammonia whilst producing both low emissions and high efficiencies in large power generation devices, thus efficiently enabling the recovery of hydrogen and reconversion of stranded, green energy that can be fed back to the grid. Tackling these problems can resolve one of the most important barriers in the use of such a molecule and storage of renewable energies. Countries such as Japan have engaged in ambitious programs to resolve these issues, aiming for large power units to run on ammonia by 2030. Thus, European counterparts, led by UK innovation, need also to engage in these technological advancements to fully unlock a hydrogen, cost-effective economy. Therefore, this project seeks to establish fundamental results that will ensure the development of an improved combustor for the use of ammonia to produce low NOx emissions combined with low ammonia slip. Hydrogen production, which will be generated through the combustion process of NH3, will also serve to increase power outputs, thus enabling the production of large power in compact systems, raising efficiency and decreasing overall cost. Improvement techniques will be assessed in currently deployed systems (Siemens gas turbines) to determine the feasibility of implementation in these devices, cutting both costs and times for units that can be employed to use ammonia as fuel in the near future. The novel combustion system proposed will be also integrated into a new ammonia micro gas turbine. The system will be combined with novel thermodynamic principles that will lead into a trigeneration cycle (cooling, power and heat) to unlock all the potential benefits of ammonia, whilst raising even more the efficiency of the system, thus creating a unique, competitive technology that can be implemented to support the hydrogen transition with negligible carbon footprint and environmental penalties. The project will be supported by companies of international reputation (Siemens, Yara, National Instruments) and UK-European innovation enterprises looking for new areas of development (Hieta, Scitek, CoolDynamics) with the creation of unique, innovative products needed for the implementation of ammonia combustion systems and humidified ammonia-hydrogen cycles. Moreover, the outcome of the project will be ensured via Open Access documentation with bespoke numerical and experimental results that will be supplemented by series of high impact publications and seminars, thus increasing awareness of the importance of using ammonia as part of the energy mix of the following decades, having the UK as core of these developments.

The CDT in Advanced Automotive Propulsion Systems will produce the graduates who will bring together the many technical disciplines and skills needed to allow propulsion systems to transition to a more sustainable future. By creating an environment for our graduates to research new propulsion systems and the wider context within which they sit, we will form the individuals who will lead the scientific, technological, and behavioural changes required to effect the transformation of personal mobility. The CDT will become an internationally leading centre for interdisciplinary doctoral training in this critical field for UK industrial strategy. We will train a cohort of 84 high quality research leaders, adding value to academia and the UK automotive industry. There are three key aspects to the success of the CDT - First, a diverse range of graduates will be recruited from across the range of first degrees. Graduates in engineering (mechanical, electrical, chemical), sciences (physics, chemistry, mathematics, biology), management and social sciences will be recruited and introduced to the automotive propulsion sector. The resulting skills mix will allow transformational research to be conducted. Second, the training given to this cohort, re-enforced by a strong group working ethos, will prepare the graduates to make an effective contribution to the industry. This will require training in the current and future methods (technical and commercial) used by the industry. We also need the graduates to have highly developed interpersonal skills and to be experienced in effective group working. Understanding how people and companies work is just as important as an understanding the technology. On the technology side, a broad system level understanding of the technology landscape and the relationship between the big picture and the graduate's own expertise is essential. We have designed a programme that enriches the student's knowledge and experience in these key areas. Third, underpinning all of these attributes will be the graduate's research skills, acquired through the undertaking of an intensive research project within the new £60 million Institute for Advanced Automotive Propulsion Systems (IAAPS), designed from the outset to provide a rich collaborative environment and add value to the UK economy. IAAPS will be equipped with world leading experimental facilities designed for future powertrain systems and provides dedicated space for industry and academia to collaborate to deliver research valued at over £100 million during the lifetime of the CDT. The cohort will contribute to and benefit from this knowledge development, providing opportunities to conduct research at a whole system level. This will address one of the most pressing challenges of our age - the struggle to provide truly sustainable, affordable, connected, zero emissions transport needed by both industrialised and emerging economies. To enable these benefits we request funding for 40 studentships and the infrastructure to provide a world class training environment. The university will enhance this through the funding of an additional 20 studentships and access to research facilities, together valued at £5 million. Cash and in-kind contributions from industrial partners valued at a total of £4.5 million will enhance the student experience, providing 9 fully funded PhD places and 30 half funded places. The research undertaken by the students will be co-created and supervised by our industrial partners. The people and research outputs that from the CDT will be adopted directly by these industrial partners to generate lasting real world impact.

BONSAI is an ambitious 3-year research project aimed at investigating the fundamental heat and mass transfer features of boiling flows in miniaturised channels. It combines cutting-edge experiments based on space/time-resolved diagnostics, with high-fidelity interface-resolving numerical simulations, to ultimately provide validated thermal-design tools for high-performance compact evaporators. The proposed project assembles multidisciplinary expertise of investigators at Imperial College London, Brunel University London, and the University of Nottingham, with support from 3 world-leading research institutes: Alan Turing Institute, CERN (Switzerland) and VIR2AL; and 11 industry partners: Aavid Boyd Thermacore, Alfa Laval, CALGAVIN, HEXAG&PIN, HiETA, Hubbard/Daikin, IBM, Oxford nanoSystems, Ricardo, TMD and TTP. The recent trend towards device miniaturisation driven by the microelectronics industry has placed an increasing demand on removing higher thermal loads, of order of MW/m2, from areas of order cm2. In some applications (e.g. refrigeration) new 'green' refrigerants are needed, but in small volumes due to flammability or cost, while in others (e.g. batteries for EV and other applications) non-uniform or unsteady heat dissipation is highly detrimental to performance and lifetime. Flow boiling in multi-microchannel evaporators promises to meet such challenging requirements with low fluid volumes, also allowing better temperature uniformity and smaller pumping power, in systems that go well beyond the current state-of-the-art. Due to significant industrial (heat exchange) and environmental (efficient energy use) interest, the understanding of boiling heat transfer has improved in recent years, with focus on flow pattern transitions and characteristics, pressure drop, and heat transfer performance. However, our current understanding is simply insufficient to facilitate the wider use of these micro-heat-exchangers in industry, which remains unexploited. BONSAI has been tailored specifically to address the fundamental phenomena underlying boiling in miniaturised devices and their relevance to industrial design. The challenges to be addressed include the impact of channel shape and surface characteristics on flow instabilities, heat transfer and pressure drop, and the relationship between the time-dependent evolution of the liquid-vapour interface, thin liquid-film dynamics, flow field, appearance of dry vapour patches, hot spots, and local heat transfer characteristics. The extensive experimental/numerical database generated will be exploited via theoretical and novel machine-learning methods to develop physics-based design tools for predicting the effects of industrially-relevant thermohydraulic parameters on system performance. The collaboration with our partners will ensure alignment with industrial needs and accelerate technology transfer to industry. In addition, HiETA will provide Metal Additive Manufacturing heat sinks that will be assessed against embossing technologies as ways of mass-producing microchannel heat exchangers, Oxford nanoSystems will provide nano-structured surface coatings, and IBM will support visits to their Research Labs focussed on efficient parallelisation of the numerical solver and scale-out studies. The proposed research will not only enable a wider adoption of two-phase thermal solutions and hence the meeting of current and future needs across industrial sectors, but also will lead to more efficient thermal management of data-centres with associated reduction in energy consumption and carbon footprint, and the recovery and reuse of waste heat that is currently being rejected. This will constitute an important step towards meeting the UK's emission targets by 2050. Additionally, BONSAI will integrate with EPSRC Prosperity Outcomes of Delivery Plan 2016-20 and enable technological advances in relation to the Manufacturing the Future theme, contributing to a Productive and Resilient Nation.