Nuclear Engineering and Design 277 (2014) 76–94 Contents lists available at ScienceDirect Nuclear Engineering and Design jou rn al hom epage : www.elsevier.com/locate/nucengdes Numerical analysis of steady state and transient analysis of high temperature ceramic plate-fin heat exchanger Vijaisri Nagarajan a , Yitung Chen a,∗ , Qiuwang Wang b , Ting Ma b a Department of Mechanical Engineering, University of Nevada, Las Vegas, NV 89154-4027, USA b Key Laboratory of Thermo-Fluid Science and Engineering, MOE, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China h i g h l i g h t s • Rip saw fin design is considered to be the best because it has thin fins and has higher heat transfer coefficient. • Minimum principal stress and maximum safety factor are obtained for the inverted bolt fin design. • Maximum principal stress and minimum safety factor are obtained for triangular fin design. • Thermal stress has significant impact than mechanical stress. • High principal stress is found at the startup and shutdown stage. a r t i c l e i n f o Article history: Received 31 December 2013 Received in revised form 2 June 2014 Accepted 4 June 2014 a b s t r a c t In this study three-dimensional model of ceramic plate-fin high temperature heat exchanger with dif- ferent fin designs and arrangements is analyzed numerically using ANSYS FLUENT and ANSYS structural module. The ability of ceramics to withstand high temperature and corrosion makes silicon carbide (SiC) suitable candidate material to be used in high temperature heat exchanger. The operating temperature of heat exchanger is 950 ◦ C and the operating pressure is 1.5 MPa. The working fluids are helium, sulfur trioxide, sulfur dioxide, oxygen and the water vapor. Fluid flow and heat transfer analysis are carried out for steady and transient state in FLUENT. The obtained thermal and pressure load for the steady and transient state from ANSYS FLUENT are imported to ANSYS structural module to obtain the principal stress and the factor of safety. Different arrangements of rectangular fins, triangular fins, inverted bolt fins and ripsaw fins are studied. From the results it is found that the minimum stress and the maximum safety factor are obtained for inverted bolt fins. The triangular fins have the maximum principal stress and minimum factor of safety. However, the fluid flow and heat transfer analysis show inverted bolt fins and triangular fins produce higher pressure drop and friction factor. The steady state maximum princi- pal stress is 10.08 MPa, 9.90 MPa and 11.43 MPa for straight, staggered and top and bottom ripsaw fin arrangement. The corresponding safety factors are 21.80, 21.95 and 19.01, respectively. The ripsaw fin design is chosen to be the best design since it gives less stress, more safety factor, less pressure drop, friction factor and reasonable heat transfer rate. From the results it is also found that thermal stress is more significant than the mechanical stress. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Compact heat exchangers (CHEs) play an important role in the field of aerospace, transportation and other industries. The need for lightweight, space saving and economical heat exchang- ers has driven to the development of compact surfaces. Due to their improved effectiveness, smaller volume, higher surface ∗ Corresponding author. Tel.: +1 7028951202. E-mail address: yitung.chen@unlv.edu (Y. Chen). area density and power savings the compact heat exchangers are widely used today. Surface area density greater than 700 m 2 /m 3 is achieved by incorporating fins, ribs and external surfaces in the heat exchangers (Hesselgreaves, 2001). There are many types of compact heat exchangers like plate heat exchanger, tube fin heat exchanger, spiral heat exchanger, printer circuit heat exchangers which are used in the industry. Plate-fin heat exchanger is a type of compact heat exchanger made of block of alternating layers of corrugated fins separated by parting sheets. The fins in the compact heat exchangers help in periodic starting and development of laminar boundary layers http://dx.doi.org/10.1016/j.nucengdes.2014.06.016 0029-5493/© 2014 Elsevier B.V. All rights reserved.