Heat Transfer Enhancement of Supercritical Carbon Dioxide and Liquid Lead Bismuth Eutectic Compact Heat Exchanger

Lead cooled fast reactor (LFR) is the fourth generation reactor system with great development potential; Supercritical carbon dioxide (S-CO₂) Brayton cycle is also considered as the most promising energy system due to its high efficiency and compactness, good flexibility. Their combination is undoubtly considered as one of the most ideal power cycles. In this union system, the intermediate heat exchanger plays a key role in the entire power system. Considering the thermo-physical properties and heat transfer behaviors in both S-CO₂ and liquid lead bismuth eutectic (LBE) are significantly different, an asymmetric compact coupled heat exchanger learning from Honeycomb structure is proposed. Then the effect of Reynolds number on the coupling heat transfer is discussed. It is found that the thermal resistance mainly exists in the cold side. In order to enhance the heat transfer in the S-CO₂ side, wave channels are used on the cold side. The results show that the wave channels can significantly improve the field synergy of the fluid near the wall; With the increase of wave amplitude, the heat transfer coefficient and the friction factor of the cold side channel increases; The comprehensive heat transfer coefficient PEC is used to evaluate the heat transfer behavior. When the PEC number is the largest, the overall heat transfer coefficient of the heat exchanger is 1.56~1.81 of the straight channel in the range of Re=86700~145000.