Molten salt and S-CO2 are important high temperature heat transfer media, but molten salt/ SCO2 heat exchanger was seldom reported. In present paper, heat transfer in zigzag printed circuit heat exchanger with molten salt and S-CO2 is simulated and analyzed. Along flow direction, local heat transfer coefficient of S-CO2 first decreases with Richardson number decreasing in inlet region, and then increases with turbulent kinetic energy rising in outlet region. Performance of PCHE is mainly determined by pressure drop in molten salt passage and heat transfer resistance in S-CO2 passage. In order to decrease the pressure drop of molten salt, an optimal structure with “sin” passage is proposed. Results show that molten salt pressure drop significantly decreases in the optimal passage, and overall heat transfer coefficient slightly changes, so comprehensive performance of PCHE is improved.
Keywords heat exchanger, molten salt, supercritical carbon dioxide, numerical simulation