Effect of honeycomb porous plate on critical heat flux in saturated pool boiling of highly concentrated artificial seawater

摘要

To enhance the reliability of in-vessel retention techniques during a nuclear power plant hazard, the viability of seawater as a coolant to flood the reactor pressure vessel was investigated. Pool boiling of distilled water, 3.5 wt. % artificial seawater, and 7.0 wt. % highly concentrated artificial seawater was performed on a 30-mm-diameter Cu bare surface (BS) with a honeycomb porous plate (HPP). The results revealed an increase in the critical heat flux (CHF) with both artificial seawater solutions, on the BS, when compared with distilled water. The improvement of surface wettability by sea salt deposits was assumed as the main reason for the improvement. A significant enhancement in the CHF was achieved with distilled water and 3.5 wt. % artificial seawater owing to the capillary properties of HPP and the separation of the liquid and vapor phases near the heated surface. When the HPP was employed with 7.0 wt. % highly concentrated artificial seawater, the performance did not improve. Although experiments with a honeycomb solid plate suggested that a high concentration of sea salt can clog the micropores in the HPP walls, resulting in loss of its capillary properties, highly concentrated artificial seawater still presented a better performance than distilled water in all cases investigated.