Abstract
The zigzag channel is the uppermost channel type of an industrial printed circuit heat exchanger (PCHE). The effect of geometric properties on the flow and heat transfer performance of the channel is significant to the PCHE design and optimization. Numerical investigations were conducted on the flow and heat transfer characteristics of supercritical CO2 (sCO2) in semicircular zigzag channels by computational fluid dynamics method. The shear stress transfer (SST) k–ω model was used as turbulence model and the National Institute of Standards and Technology (NIST) real gas model with REFPROP database was used to evaluate the thermophysical parameters of sCO2 in this numerical method. The effectiveness of the simulation method is verified by experimental data. Thermal hydraulic performance for zigzag channels with different pitch lengths, bending angles, and hydraulic diameters are studied comparatively based on this numerical method, with the boundary conditions which cover the pseudocritical point. The comparison results show that reducing the bending angle and pitch length will strengthen the effect of boundary layer separation on the leeward side of the wall and enhance the heat transfer performance, but the pressure drop of the channel will also increase, and the decrease of channel hydraulic diameter is beneficial to the heat transfer enhancement, but it is not as significant as that of the straight channel.
Highlights
A printed circuit heat exchanger (PCHE) is a type of compact heat exchanger with high efficiency, high application pressure, and high application temperature
This paper aims at modeling the forced convection heat transfer of CO2 within the zigzag channels, which are the main channel type of PCHE, and studies the effects of its main geometric parameters on its internal flow and heat transfer parameters, especially near the pseudocritical point
Through the previous analysis cases, we found that the separation of boundary layer promotes the mixing and diffusion in the fluid and enhances the heat transfer performance of the zigzag channel
Summary
A printed circuit heat exchanger (PCHE) is a type of compact heat exchanger with high efficiency, high application pressure, and high application temperature. It was invented in Australia in 1980 and promoted for commercial application by Heatric. It has broad application prospects in the fields of ultra-high-temperature gas-cooled reactors, floating liquefied natural gas storage units, and other industrial energy [1]. CO2 is a nontoxic and inexpensive gas It has excellent thermophysical properties (high specific heat, high thermal conductivity, and low viscosity) near the pseudocritical point, as shown, which can considerably enhance the heat transfer without sacrificing the hydraulic performance [5]. The application of CO2 in PCHE has become the focus of researchers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
