Speakers

Prof Vladimir Strezov is professor in environmental science at the School of Natural Sciences, Faculty of Science and Engineering at Macquarie University. He holds degrees in Mechanical and Chemical Engineering with expertise in renewable energy, environmental assessment, air and water quality, and sustainable development. He has published 6 scholarly books and over 300 publications. Prof Strezov is a Fellow of the Institution of Engineers Australia, and Fellow of the Australian Institute of Energy.

Professor Zhibin Yu currently holds the Chair of Energy Engineering in the Department of Mechanical and Aerospace Engineering at the University of Liverpool. He leads the Energy Research Cluster within the School of Engineering and holds a prestigious Royal Society Industrial Fellowship (2023–2027). Prior to this, he held academic positions at the James Watt School of Engineering, University of Glasgow: Lecturer (2012–2017), Senior Lecturer (2017–2019), and Professor of Thermal Energy (2019–2023). His research focuses on thermal energy technologies, with particular interest in the underlying thermodynamic, heat transfer, and fluid-dynamic challenges. He is committed to developing innovative solutions for sustainable heating, cooling, and power generation, with expertise spanning heat pumps, refrigeration, energy storage, district heating and cooling networks, organic Rankine cycle systems, and thermoacoustics. Professor Yu has led or contributed to over 35 research projects with a combined value exceeding £30 million, funded by EPSRC, Innovate UK, and the European Commission. He has published more than 180 research papers and is the inventor of the Flexible Heat Pump Cycle (PCT reference: WO2022069581A1), a technology that enables the next generation of high-efficiency, flexible heat pumps. He currently serves as Associate Editor for Applied Energy (Elsevier) and npj Thermal Science and Engineering (Springer Nature), Subject Editor for Applied Thermal Engineering (Elsevier), and Section Editor-in-Chief for Frontiers in Thermal Engineering. He also sits on the editorial boards of Energy Reports (Elsevier) and the International Journal of Green Energy (Taylor & Francis). Professor Yu is a Board Director of the International Association for Green Energy, and he served as Chair of the 15th International Green Energy Conference, hosted at the University of Glasgow.

Speech Title: The Flexible Heat Pump Technology: Enhanced Efficiency and Broad Applications

Abstract: Heat pumps are widely recognised as a key technology for decarbonising heat and achieving net-zero emissions. However, their adoption has been slower than expected. Most commercial heat pumps are based on the conventional Evans-Perkins vapour compression cycle, originally developed for refrigeration. As the temperature lift between the heat source and sink increases, the coefficient of performance (COP) of single-stage heat pumps drops significantly—primarily due to throttling losses, which scale with the square of the temperature lift. To enable widespread deployment, further innovation is needed to improve both the performance and cost-effectiveness of heat pump systems. In this talk, Professor Yu will present an up-to-date overview of recent research advances in heat pump technologies, followed by a discussion of the key challenges and emerging opportunities in the field. He will then introduce his work on the invention and development of Flexible Heat Pump technology, which integrates thermal energy storage into the conventional Evans-Perkins cycle. This approach enables the recovery, storage, and reuse of thermal energy from the warm liquid refrigerant leaving the condenser. Thermodynamically, it resembles a two-stage vapour compression cycle with subcooling and flash gas removal—offering an innovative solution to the persistent issue of throttling losses in high-temperature applications. The integration of in-cycle heat recovery and storage opens up a wide range of new applications, delivering substantial energy savings and enhanced operational flexibility.