Thermal hydraulic performance analysis of a printed circuit heat exchanger using a helium–water test loop and numerical simulations

• Published in: Applied thermal engineering 2011-12, Vol.31 (17), p.4064-4073
• Main Authors: Kim, In Hun, NO, Hee Cheon
• Format: Article
• Language: English
• Subjects: Applied sciences; Computational fluid dynamics; Computer simulation; Devices using thermal energy; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fanning factor; Fission nuclear power plants; Fluid flow; Heat exchangers; Heat exchangers (included heat transformers, condensers, cooling towers); Heat transfer; Heat transfer enhancement; Installations for energy generation and conversion: thermal and electrical energy; Mathematical models; Nusselt number; Pressure drop; Printed circuit heat exchanger (PCHE); Reynolds number; Theoretical studies. Data and constants. Metering; Thermal–hydraulic performance; Three dimensional
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2011.08.012

A Printed Circuit Heat Exchanger (PCHE) is a promising candidate with excellent performance to satisfy the heat exchanger requirements of High Temperature Gas Cooled Reactors (HTGRs). These heat exchangers are composed of many micro-wavy channels, which cause an increase in both heat transfer and pressure drop. We investigated thermal-hydraulic performance of the PCHE in a helium-water condition through experimental tests and numerical simulations with horizontal and vertical arrangements. Experiments were performed in laminar region. Pressure drop and temperatures were measured during experiments at the inlet and outlet of the helium and the water sides, respectively. We obtained three-dimensional (3-D) numerical solutions with periodic boundary conditions using the computational fluid dynamics (CFD) code, FLUENT. The numerical simulation range was expanded to Reynolds number of 2500 through the 3-D CFD simulations, after the numerical solutions were validated against experimental data. A proposed Fanning factor correlation in the PCHE, in terms of Reynolds number and a correction factor, predicts the local pitch-averaged Fanning factor in the helium and the water sides in the range of less than 0.97% and 0.65%, respectively. A Nusselt number correlation with an average error of 3.589% was also developed in terms of Reynolds number and Prandtl number. ► We investigated thermal-hydraulic performance of a PCHE in a helium-water condition. ► We used local approach to increase the accuracy of correlations. ► We proposed the correlations of Fanning factor and Nusselt number in laminar region. ► We seriously mentioned mal-flow distribution in the water side during PCHE operation.