Heat transfer enhancement of subcooled pool boiling with self-rewetting fluid

Abstract

To clarify the fundamental heat transfer characteristic and heat transfer enhancement of subcooled pool boiling with self-rewetting fluid (SRWF), using dilute heptanol aqueous solution as SRWF, a serial boiling experiments have been carried out. During the experiments, a boiling system using a horizontal heated wire was employed. The boiling performance of SRWF with different subcooling (1°C, 5°C, 10°C, 15°C) and different concentrations (0, 0.01wt%, 0.05wt%, 0.1wt% heptanol aqueous solution) have been demonstrated in this paper. The experimental results show that, the higher subcooled temperature leads to the better heat transfer performance, and it can effectively prevent the dry out phenomenon. Due to better surface tension and concentration gradient, the 0.1wt% heptanol aqueous solution shows the best critical heat flux, which is beneficial for increasing the dry out limit. With a high speed video camera, the nucleation boiling process on the heated wire has been recorded. Furthermore, it is found from the boiling phenomenon that, the boiling bubbles of SRWF are visualized to be much smaller and more, which is conducive to the application in small thermal devices.