Numerical investigation of three-tube intertwined HX design

Abstract A three-tube intertwined heat exchanger design featuring simplicity, robustness, and efficient heat-transfer properties. The design is derived from the twined tube heat exchanger design with the addition of a third tube in the shell section. To meet the required heat load, multiple modules can be configured within a shell area. An experimentally validated twined tube heat exchanger computational fluid dynamics model is utilized to perform the thermal-hydraulic analysis on the full-scale numerical simulation for single-phase forced convection. The thermal-hydraulic performance parameters of the three-tube intertwined heat exchanger are evaluated for mass fluxes varying from 163 kg/m 2 s to 279 kg/m 2 s. The results are compared with those of the straight tube and twined tube heat exchanger configurations. The three-tube intertwined heat exchanger demonstrates a 55 % higher performance factor than the straight tube heat exchanger and 16 % higher than the twined tube heat exchanger. The three-tube intertwined heat exchanger exhibits a performance factor of 2.49, higher than the straight tube and twined tube heat exchangers. Moreover, without compromising the performance, this design facilitates enhanced heat duty for the same geometrical and process parameters as the twined tube heat exchanger. The design could be deployed in the advanced nuclear reactors.