Thermal design of printed circuit heat exchanger used for lead-bismuth fast reactor

Printed circuit heat exchanger (PCHE) has the potential to replace the traditional heat exchangers in lead–bismuth fast reactors due to the high compactness. In this work, a segmented Log-Mean Temperature Difference (LMTD) method is applied to design a PCHE used for a 280 MWth lead–bismuth fast reactor. The structural strength is checked based on the ASME Code Case. The optimal design of heat exchanger is conducted at different inlet velocities of lead–bismuth eutectic (LBE) and channel diameters. Meanwhile, the variations of LBE-side and water-side Reynolds numbers, convective heat transfer coefficients, mass and volume of the PCHE are analyzed, respectively. The results show that the heat transfer rate per unit volume could reach 181 MW/m3, nearly eight times of shell-and-tube heat exchanger applied to the same lead–bismuth fast reactor, and two times of compact plate heat exchanger with the same working fluids. When the heat transfer rate and the pressure loss are satisfied, the larger the inlet velocity of LBE or the smaller the channel diameter is, the smaller the total volume and mass of the PCHE are.