防止蒸汽锅炉铸铁省煤器内介质沸腾的措施

对小型蒸汽锅炉省煤器内的介质沸腾问题进行了探讨，详细分析了介质沸腾的现象、原因，提出了改进和防止措施，并且应用于实践，收到了明显的经济效益和社会效益。

堆芯氧化腐蚀产物沉积层内两相沸腾传热传质特性

多孔形貌的氧化腐蚀产物沉积层一方面会增大热阻导致传热恶化,另一方面硼吸附会导致堆芯功率分布发生改变,因此,准确预测沉积层内的传热传质特性对反应堆的经济性和安全性有重要意义。本文将多孔介质层内的沸腾传热、毛细流动、溶质输运、化学反应等多物理现象进行耦合,提出了预测沉积层内的传热传质特性的高保真方法。冷却剂在毛细作用下进入多孔介质,并在烟囱表面蒸发。溶质随毛细流扩散进入多孔介质并被浓缩,各溶质间保持化学平衡。上述方法可以合理预测沉积层内的温度、流速、压力和溶质浓度分布,与Haq等相比,相对误差在±0.83%以内。在此基础上,分析了沉积层孔隙率、厚度、烟囱半径、烟囱直径等形貌参数对传热传质的影响规律。

Investigation of Enhanced Boiling Heat Transfer from Porous Surfaces

Experimental investigations of boiling heat transfer from porous suffaces at atmospheric pressure were performed. The porous surfaces are plain tubes covered with metal screens, V-shaped groove tubes covered with screens, plain tubes sintered with screens, and V-shaped groove tubes sintered with screens.The experimental results show that siatering metal screens around spiral V-shaped groove tubes can greatly improve the boiling heat transfer. The boiling hysteresis was observed in the experiment. This paper discusses the mechanism of the boiling heat transfer horn those kinds of porous surfaces stated above.