Defrosting for Air Source Heat Pump

Mengjie Song is a Professor in the Department of Energy and Power Engineering, as well as a Teli Young Scholar and the Director of the Frost Lab in the School of Mechanical Engineering at the Beijing Institute of Technology, China. He is also the Editor-in-Chief of Recent Patents on Mechanical Engineering (EI, Scopus), Associate Editor of Frontiers in Energy Research (SCI, IF=2.746). He also works as DECRA Research Fellow at the Sustainable Buildings Research Centre (SBRC) in the Faculty of Engineering and Information Sciences at the University of Wollongong, Australia, and as a Guest Professor of Tomas Bata University in the Czech Republic. Prof. Song has worked for over a decade on the mechanism study of heat and mass transfer coupled with flow. On the topic of frosting and defrosting for air source heat pump, he proposed a series of definitions to describe thermophysical phenomena, such as even/uneven frosting/defrosting, and frosting/defrosting evenness value. His current research interests include solidification of water droplets at different scales and (anti-/de)icing for aircraft surface, and frosting and defrosting for a multi-circuit heat exchanger in refrigeration systems. He has published 122 journal articles and participated in projects from China, Hong Kong, Singapore, Japan, and Australia, handling a total of over 17 million yuan in funding, including 12 as PI. Recently, he was selected for the World’s Top 2% Scientists 2021 (Singleyr) list. Professor Deng Shiming obtained his PhD from London South Bank University, UK, in 1991. He has been a faculty member in the Department of Building Services Engineering at The Hong Kong Polytechnic University since October 1992. He is now a full professor, a fellow of the Hong Kong Institution of Engineers (HKIE), and a member of American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). Prof Deng’s research interests include building energy efficiency, indoor thermal comfort, and modelling and control of direct expansion based air conditioning and heat pump systems. He is currently on the Editorial Board of International Journal of Applied Energy, and was a guest Editor of Energy and Buildings for a special issue of the thermal comfort in sleeping environments. Professor Deng has published two book chapters and over 250 papers including 170 journal papers.

1. Introduction 2. Previous Related Work - A Review 3. Uneven Defrosting on the Outdoor Coil in an ASHP 4. Modelling Study on Uneven Defrosting 5. Investigation of Effect on Uneven Defrosting Performance 6. Frosting Evenness Coefficient 7. The Influence of Refrigerant Distribution on Defrosting 8. Energy Transfer During Defrosting 9. Defrosting Control Strategy 10. Technoeconomic Performance 11. Conclusions and Future Work