Heat transfer performance of two-phase immersion cooling by breathing phenomena with different pore structures of lotus copper

The purpose of this study is to enhance the critical heat flux of two-phase immersion cooling in saturated pool boiling. A lotus copper is joined onto a grooved heat transfer surface to prevent the coalescence of generated bubbles. In this paper, we experimentally investigate the influence of the thicknesses of the lotus copper on the critical heat flux. The thicknesses are 1 mm and 3 mm. We achieve the critical heat flux of 492 W/cm2 in the case of thickness of 1 mm (the average pore size: 0.65 mm). On the other hand, the critical heat flux is 409 W/cm2 in the case of thickness of 3 mm (the average pore size: 0.77 mm). The cooling performance could be enhanced by reducing the thickness of the lotus copper by making it easier to supply much coolant by the breathing phenomenon.