【摘要】 研究了添加剂对垂直管内流动沸腾传热的影响,选用W/O型聚丙烯酰胺(简称PAM)和十八烷胺(简称ODA)为添加剂,研究添加剂水溶液的性质、添加剂浓度、流速、热通量、聚合物分子量等因素对流动沸腾传热的影响.采用X光射线光电子能谱仪测试了添加剂分子在管壁上的吸附情况,并对壁面特性进行了分析.研究结果表明,W/O型聚丙烯酰胺和十八烷胺都具有强化流动沸腾传热的性能,而且有最佳浓度范围。PAM还具有减阻性能,因而可提高流速来强化流动沸腾传热。更多还原

【Abstract】 The effect of additives on the flow boiling heat transfer in the vertical tube has been studied. Polyacrylamide (PAM) and octadecrylamine (ODA) were used as additives for enhancing heat transfer. Effects of fluid properties, concentration and molecular mass of PAM, and heat flux on flow boiling heat transfer were studied. In order to analyse the mechanism of enhancement of boiling heat transfer with additives, the diagram for binding energy was measured by XPS.The experimental results indicate that both PAM and ODA enhance the flow boiling heat transfer of water,and have an optimum range of concentration PAM can reduce the drag of flow boiling to enhance boiling heat transfer by increasing flow velocity.更多还原