Numerical Investigation of Thermal Hydraulic Performance of Printed Circuit Heat Exchanger of Periodic Diamond Channel Shape

Abstract

One of the most recently important heat exchangers is the Printed circuit heat exchanger especially in the nuclear power plant and aerospace applications due to its very compact geometry and small print foot. This paper presents a 3D numerical investigation on the thermo-hydraulic performance of PCHE with new non-uniform channel design configuration. The new channel design is a rectangular cross section with repeated converging diverging sections or periodic diamond shape. The influence of three design parameters on the heat exchanger performance was studied and optimized, pitch length (p), length ratio (β) and the converging diverging angle (α). The computational models investigated in this study based on the operating conditions of the intermediate heat exchanger of very high temperature gas cooled reactor with helium as the working fluid under operating pressure of 3Mpa and inlet temperature of 800 K. The Reynolds number varied from 200 to 2000. Different Pitch lengths were used (1.59, 3.18, 6.36, and 12.73) mm, and different C-D angle (0, 4.5, 6, 7.5, 9, 10.5 and 12) and also different length ratios were used (0.2, 0.25 and 0.333). Three performance parameters were studied the Nusselt number, friction factor and the overall performance evaluation factor. Results show that the thermal performance enhanced with decreasing the pitch length and with increasing C-D angle and it was shown that this enhancement was found only at high Reynolds number above 1400. The best performance obtained at p=3.18, α=6 and β=0.25 based on the overall evaluation performance.

Enhancement of Thermal Efficiency on a Upstream Wedge Ribs Microchannel using Lattice Boltzmann Approach

“…With the use of two layers of fins of varying thicknesses, Zhang et al [20] have created a structure that may efficiently direct more cryogenic fluid to the bottom layer, lessen pressure drop loss, and enhance high heat transfer. Aljelawy et al [21] investigated the thermal-hydraulic performance of printed circuit heat exchangers and the thermal performance is enhanced by the reduction in the pitch length, as shown by their results. Taher et al [22] also discussed the simultaneous effects of thermal and hydrodynamic behaviors on various kinds of roughness in microchannel using the Lattice Boltzmann approach.…”

Numerical Investigation of Thermal-Hydraulic Performance of Printed Circuit Heat Exchanger with Different Fin Shape Inserts

“…The new PCHE with S-shaped fins consumes 3.3 times less space than the previous hot water supply and results in a 37 percent reduction in CO 2 pressure drop and a tenfold reduction in water pressure drop. Aljelawy et al [16] performed a numerical investigation of PCHE thermal-hydraulic performance using periodic diamond (converging-diverging) channels. Three geometrical parameters were studied: the pitch length of periodic section, length ratio of converging-diverging section and the angle of opening with Helium as the working fluid.…”