Scientific foundations of vacuum technique: by Saul Dushman. 882 pp., 16 × 23 cm., illustrations. New York, John Wiley & Sons, 1949. Price, $15.00

Abstract

External Reactor Vessel Cooling has been a key severe accident management strategy to prevent the damage of the reactor vessel. Saturated pool boiling heat transfer coefficients and critical heat flux (CHF) were measured from the downward facing structured surface of interconnected-grooves with triangular array cavities (IGTAC surface) in deionized water to enhance the CHF. Four IGTAC surfaces were investigated at inclination angles of 5°, 30°, 45°, 60° and 90° (vertical). The experimental results indicated that the CHF increases with the increasing inclination angle. The highest CHF at inclination angle of 5° on downward facing IGTAC surface could reach 1258.4 kW/m2, which was over 2 times of that on a plain surface. The CHF on IGTAC surface did not appear at larger inclination angles when the heat flux reached 2400 kW/m2, which is the limit of the experimental apparatus. The IGTAC surfaces can form a liquid-vapor conversion path with the cavities as stable nucleation sites and the interconnected grooves as the cooling water supply pathways, which results in a significant boiling heat transfer enhancement and CHF increase. It is shown that deeper groove depth and larger cavity diameter will enhance the nucleate boiling heat transfer (NBHT) and CHF on IGTAC surfaces within the current dimension parameter range.