Microchannel heat exchanger has many advantages such as good heat transfer performance and compact structure. However, the flow and heat transfer performance of the molten salt side of the heat exchanger is poor. In order to improve the flow and heat transfer performance of the molten salt side, the airfoil microchannel molten salt heat exchanger is strengthened and numerically analyzed based on the field synergy principle. In this contribution, the binary nitrate (Solar Salt), which is a mixture of 60% sodium nitrate and 40% potassium nitrate, is used as the hot side fluid. Firstly, the local field synergy angle distribution is calculated. Then, the effects of the inlet flow velocity and the inlet temperature on the field synergy are analyzed. Finally, the positions with poor local field synergy angle are strengthened. The results show that when the inlet flow rate is in the range of 0.005-0.013 kg/s (Re=2810-7307), the field synergy angle of airfoil microchannel heat exchanger increases with the increase of inlet flow rate and inlet temperature. The whole field synergy angle of the enhanced heat exchanger decreases by 3.73° and the PEC increases by 2.25%.
Key words
solar thermal power /
molten salts /
numerical simulation /
microchannel heat exchanger /
field synergy principle /
heat transfer enhancement
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