Effect of front and side confinement on a vertical heated plate with two-phase cooling

A test bench containing a 64 ×\times 40 mm2^2 vertical heated plate is filled with 3M Novec7000 dielectric fluid at atmospheric pressure. The wall heat fluxes are varied from 0 to 20 W.cm−2^{-2} . Temperature measurements and heat flux calculations are made using thermocouples. Observations are done using a high-speed camera through a glass window. The heated plate can be moved using a micrometric screw. Thus, the confinement between the heated plate and the glass window can be varied from 0.5 to 15 mm.

New experiments have been conducted to study the flow of the refrigerant and its effect on the dissipation of heat fluxes. U-shape PVC plates have been used to border the heated plate. High speed visualisations show that the flow trajectory is forced to cycle only along the heated part and not around. This additional side confinement increases the heat transfer between the wall and the fluid in comparison to the configuration without the U-shape plates. However, the critical heat flux is decreased. Indeed, it may be explained by the recirculating flow, strong enough to pull bubbles down, which could bring the bubble crowding and coalescence earlier.

Work In Progress