Prof. Huifang Kang

Beijing Institute of Technology, China

E-mail: kanghf2009@bit.edu.cn

Bio

Hui Fang Kang, Ph.D., is an Associate Professor and Ph.D. supervisor at the School of Mechanical Engineering and Vehicular Engineering, Beijing Institute of Technology. She has been engaged in teaching and research in the field of energy and power engineering for many years. Her research interests mainly include new energy power systems and hydrogen energy technologies, refrigeration and cryogenic engineering, thermoacoustic technology, liquid hydrogen storage and transportation, as well as water and thermal management of fuel cells and thermal management of multidisciplinary power systems.
Focusing on frontier topics such as cryogenic thermoacoustic refrigeration, liquid hydrogen storage and supply systems, and advanced thermal management technologies, Dr. Kang has undertaken numerous research projects, including those funded by the National Natural Science Foundation of China (NSFC), the Beijing Natural Science Foundation, the Doctoral Program Foundation of the Ministry of Education, sub-projects of the National Key R&D Program of China, key and major projects supported by the Science and Technology Commission of the Central Military Commission, and other major national defense research programs.
In terms of academic achievements, Associate Professor Kang has made a series of innovative contributions in the fields of energy conversion, thermal science, and cryogenic engineering. She has published more than 50 SCI-indexed papers in prestigious international journals, including Applied Energy, Journal of Power Sources, Energy Conversion and Management, Applied Thermal Engineering, and International Journal of Heat and Mass Transfer, among which over 30 papers were published as the first author or corresponding author. In addition, she has been granted more than 40 Chinese invention patents.

Title

Self-excited thermoacoustic oscillations enable enhanced phase transitions

Abstract

Evaporation and condensation processes are constrained by heat and mass transfer boundary-layer resistance, resulting in low heat and mass transfer rates at the gas–liquid two-phase interface. This makes it difficult to further miniaturize thermal engineering devices such as seawater desalination, waste heat recovery, and refrigeration/heat pump systems. This paper proposes a new method for enhancing heat and mass transfer. Without increasing system complexity, the proposed method creates an acoustic resonance structure by adjusting the structural dimensions of existing thermal devices. The temperature difference within the system itself is used to excite acoustic waves, which in turn enhance heat and mass transfer inside the thermal equipment. Using a humidification–dehumidification seawater desalination system as a case study, this paper establishes a theoretical model based on acoustic–electric analogy, revealing the relationship between system structural parameters and the onset conditions of self-excited oscillation. In combination with a dimensionless acoustic power criterion, the contribution of phase-change mass transfer in wet porous media to acoustic power generation is analyzed. An experimental platform is further constructed to reveal and verify the mechanism by which self-excited acoustic waves enhance heat and mass transfer. The experimental results show that, in the absence of self-excited acoustic waves, the system water production rate is 19.7 g/h. After self-excited acoustic waves are successfully generated, the water production rate increases to 51.92 g/h, representing a 163% improvement compared with the no-acoustic-wave condition. This work provides a new approach for enhancing heat and mass transfer processes driven by low-grade thermal energy. The method requires no external acoustic source, features a simple structure and strong environmental adaptability, and offers system-level coupled enhancement.