Optical and thermal visualization of quench front on hot wall during reflood

Abstract

A detailed rewetting phenomenon is observed using refrigerant R141b as the working fluid. Rewetting phenomenon is visualized based on total reflection images and high-speed images. Furthermore, two-dimensional profiles of wall temperature and heat flux at the heated surface are obtained using a high-speed infrared thermometry camera. These images were temporally and spatially synchronized, so that the relationship between the hydraulic and thermal behaviors of the rewetting phenomenon could be examined in detail. The results show that a mesh-shaped wetting structure is formed near the quench front and the heated surface above the quench front remain in a dry state. The time variations of the temperature and heat flux at a fixed point change abruptly, and the oscillations of the temperature and heat flux increase as the quench front approaches the point. The relationship between the wall temperature and heat flux exhibits a similar trend for different flow rate conditions.