蒸汽爆炸粗混合阶段冷液中高温球传热阻力耦合特性的实验研究

采用蒸发电力模型,设计了高温颗粒同水相互作用的实验装置,进行了一系列单个,多个粒子在不同温度,不同入水初速度和不同冷液过冷度情况下的系列阻力实验,初步实验分析表明,高温颗粒在刚刚穿过冷液表面的下沉速度明显低于冷态颗粒的速度,实验值与蒸发曳力模型计算值符合较好.

Experiment Study of the Coupling Effect between Film Boiling Heat Transfer and Evaporation Drag around a High-temperature Particle in Cold Liquid during Coarse Mixing Stage of Vapor Explosion

From the view of evaporation, when a high-temperature particle is surrounded by a vapor film with different thickness circumferentially, the local evaporation rate and the local density of the vapor may have a non-spherical-symmetric distribution, which could induce a non-spherical-symmetric profile for pres-sure, and form a flow around the particle. This non-symmetric profile would bring about a resultant force on the hot particle, so as to resist its motion. For verifying the model, we constructed a special observation ex-periment facility, and performed an observation experiment by pouring one or several high-temperature parti-cles into a water pool. The facility consists of the test vessel, the furnace and the valve system. The furnace for heating the particles was designed to produce a temperature above 2500K. Observation experiments have been performed by pouring one or several Zirconia spheres at several temperatures and several diameters into a water pool. The particle falling-down speeds were recorded by high-speed camera. Comparisons have been made for the experimental and calculated results under the evaporation drag model. We found that they are nearly identical.