Experimental Study on Small Scale Printed Circuit Heat Exchanger with Zigzag Channels

Abstract

Printed circuit heat exchanger (PCHE) is a promising candidate of coolers used for SCO₂ Brayton cycle. The thermal-hydraulic performance of SCO₂ in a PCHE depends on the PCHE structure as well as the operating conditions of SCO₂ due to its dramatic variation of thermal physical properties near the pseudo-critical point. This work experimentally investigated the thermal-hydraulic characteristics of zigzag-channel PCHEs between SCO₂ and water at pressures that ranged from 8.0 to 11.0 MPa. Results showed that increasing the flow rate of SCO₂ might affect the PCHE more pronouncedly in comparison with changing the flow rate of water, indicating that the major convective thermal resistance is on the SCO₂ side. When increasing the operating pressure from 8.0 MPa to 11.0 MPa, the Nusselt numbers of PCHEs with zigzag angles of 0°, 15°, and 25° averagely decrease by 63.3%, 62.1%, and 54.0%, and the friction factors averagely decrease by 28.6%, 27.4%, and 21.0% respectively. Meanwhile, it is found that the buoyancy force is non-negligible during SCO₂ cooling process in PCHEs. In this regard, Nusselt number and friction factor correlations considering the buoyancy effect are proposed with applicable ranges.

Additional information

Funding

This work was supported by the State Key Program of National Natural Science of China (No. 51536007), the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 51721004) and the Programme of Introducing Talents of Discipline to Universities Project (No. B16038).

Notes on contributors

Wenxiao Chu

Wenxiao Chu used to study in the University of Nevada Las Vegas as a visiting scholar. He received his Ph.D. in Engineering Thermophysics from Xi’an Jiaotong University in 2017. His research interests include computational fluid dynamics and numerical heat transfer, thermal storage system and novel and compact heat exchanger design, thermal management and control system analysis, and thermal safety analysis under extreme conditions.

Xionghui Li

Xionghui Li is a Ph.D. candidate at the School of Energy and Power Engineering in Xi’an Jiaotong University. His research interest is in the design and optimization of printed circuit heat exchangers and fundamental studies on diffusion bonding technology.

Yitung Chen

Yitung Chen is a professor in the Department of Mechanical Engineering at the University of Nevada Las Vegas. He is a fellow of the ASME. His academic and industrial experiences is in numerical and experimental fluid mechanics and thermal fluid sciences covers multidisciplinary areas of mechanical, biomedical, environmental, chemical, and nuclear engineering. He is an expert in computational and experimental aspects of momentum, heat, and mass transfer. He is an associate editor of Science Bulletin and Heat Transfer Research. He is the author or coauthor of 2 books, Computational Partial Differential Equations Using MATLAB and Heat Transfer Enhancement, and 95 technical journals and 250 peer-reviewed conference proceedings. He has also contributed six book chapters. He has been invited to give more than 60 keynotes, lectures, and seminars at different international conferences and universities.

Qiuwang Wang

Qiuwang Wang is a full professor at the School of Energy and Power Engineering, Xi’an Jiaotong University. His main research interests include heat transfer enhancement and its applications to engineering problems, high-temperature heat transfer and fluid flow, transport phenomena in porous media, numerical simulation, prediction & optimization. He is now the China Delegate of Assembly for International Heat Transfer Conferences (AIHTC), a member of Scientific Council of the International Center for Heat and Mass Transfer (ICHMT), a vice president of Chinese Society of Engineering Thermophysics in Heat and Mass Transfer. He is an Associate Editor of Heat Transfer Engineering, and Editorial Board Member for Energy Conversion and Management, Applied Thermal Engineering. He is the Initiator and Chairman of International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control (IWHT) since 2011. He has also delivered more than 30 Invited/Keynote lectures in international conferences or foreign Universities. He has also been author or coauthor of more than 100 international journal papers, and authorized 19 China Invent Patents and 2 US Patents.

Ting Ma

Ting Ma is a professor at the School of Energy and Power Engineering, Xi’an Jiaotong University. He received his Ph.D. in Engineering Thermophysics from Xi’an Jiaotong University in 2012. He was a visiting scholar in the Mechanical Engineering Department at University of Nevada Las Vegas (UNLV) from Aug. 2011 to Jan. 2012, and a visiting scholar in the Mechanical Engineering Department at Virginia Tech from Mar. 2014 to Feb. 2015. His research interests include heat transfer enhancement under high temperature and high-pressure conditions, compact mini/micro-channel heat exchangers, thermoelectric power generator and cooler, computational fluid dynamics, and numerical heat/mass transfer. He has published more than 40 journal papers, and contributed two book chapters. He has been invited to give more than 10 keynotes, lectures, and seminars at international conferences and universities. He has been an Associate Editor of ASME Journal of Solar Energy Engineering, and has become a committee member of ASME Heat Transfer Division K-18 since 2018.